AbstractPurpose Although approximately one-third of agricultural equipment-related crashes occur near town, these crashes are thought to be a rural problem. This analysis examines differences between agricultural equipment-related crashes by their urban–rural distribution and distance from a town. Methods Agricultural equipment crashes were collected from nine Midwest Departments of Transportation (2005–2008). Crash zip code was assigned as urban or rural (large, small and isolated) using Rural–Urban Commuting Areas. Crash proximity to a town was estimated with ArcGIS. Multivariable logistic regression was used to estimate the odds of crashing in an urban versus rural zip codes and across rural gradients. {ANOVA} analysis estimated mean distance (miles) from a crash site to a town. Findings Over four years, 4444 crashes involved agricultural equipment. About 30% of crashes occurred in urban zip codes. Urban crashes were more likely to be non-collisions (aOR = 1.69[1.24–2.30]), involve ≥2 vehicles (2 vehicles: aOR = 1.58[1.14–2.20], 3+ vehicles: aOR = 1.68[0.98–2.88]), occur in a town (aOR = 2.06[1.73–2.45]) and within one mile of a town (aOR = 1.65[1.40–1.95]) than rural crashes. The proportion of crashes within a town differed significantly across rural gradients (P < 0.0001). Small rural crashes, compared to isolated rural crashes, were 1.98 (95%CI[1.28–3.06]) times more likely to be non-collisions. The distance from the crash to town differed significantly by the urban-rural distribution (P < 0.0001). Conclusions Crashes with agricultural equipment are unexpectedly common in urban areas and near towns and cities. Education among all roadway users, increased visibility of agricultural equipment and the development of complete rural roads are needed to increase road safety and prevent agricultural equipment-related crashes.

Keywords: Traffic accident

Abstract A large literature base has found that economic factors have important effects on traffic crashes. A small but growing branch of literature also examines the role of gasoline prices in the occurrence of traffic crashes. However, no studies have investigated the possible difference of these effects between urban and rural areas. In this study, we used the monthly traffic crash data from 1998 to 2007 at the county level in Minnesota to investigate the possibly different effects gasoline prices may have on traffic crashes per million vehicle miles traveled in urban versus rural areas. The results indicate that gasoline price effects on total crashes, property-damage-only crashes, and injury crashes are stronger in rural areas than in urban areas. Gasoline prices also significantly affect fatal crashes in both urban and rural areas; however, the difference is not significant. The results concerning the differences between urban and rural areas have important policy implications for traffic safety planners and decision makers.

Keywords: Gasoline prices

Abstract Our primary research question was whether teens obtaining their intermediate-level provisional operators permit (POP) in a graduated driver licensing (GDL) environment through driver education differed in crashes and traffic violations from teens who obtained their {POP} by completing a supervised driving certification log without taking driver education. A descriptive epidemiological study examining a census of all teen drivers in Nebraska (151,880 teens, 48.6% girls, 51.4% boys) during an eight year period from 2003 to 2010 was conducted. The driver education cohort had significantly fewer crashes, injury or fatal crashes, violations, and alcohol-related violations than the certification log cohort in both years one and two of driving following receipt of the POP. Hierarchical logistic regression was conducted, controlling for gender, race/ethnicity, median household income, urban–rural residence, and age receiving the POP. In both year one and two of driving, teens in the certification log cohort had higher odds of a crash, injury or fatal crash, violation, or alcohol-related violation. Findings support that relative to a supervised driving certification log approach, teens taking driver education are less likely to be involved in crashes or to receive a traffic violation during their first two years of driving in an intermediate stage in a graduated driver licensing system. Because teen crash and fatality rates are highest at ages 16–18, these reductions are especially meaningful. Driver education appears to make a difference in teen traffic outcomes at a time when risk is highest.

Keywords: Driver education

Abstract The primary objective of this study was to evaluate the effects of parallelogram-shaped pavement markings on vehicle speed and crashes in the vicinity of urban pedestrian crosswalks. The research team measured speed data at twelve sites, and crash data at eleven sites. Observational cross-sectional studies were conducted to identify if the effects of parallelogram-shaped pavement markings on vehicle speeds and speed violations were statistically significant. The results showed that parallelogram-shaped pavement markings significantly reduced vehicle speeds and speed violations in the vicinity of pedestrian crosswalks. More specifically, the speed reduction effects varied from 1.89 km/h to 4.41 km/h with an average of 3.79 km/h. The reduction in the 85th percentile speed varied from 0.81 km/h to 5.34 km/h with an average of 4.19 km/h. Odds ratios (OR) showed that the parallelogram-shaped pavement markings had effects of a 7.1% reduction in the mean speed and a 6.9% reduction in the 85th percentile speed at the pedestrian crosswalks. The reduction of proportion of drivers exceeding the speed limit varied from 8.64% to 14.15% with an average of 11.03%. The results of the crash data analysis suggested that the use of parallelogram-shaped pavement markings reduced both the frequency and severity of crashes at pedestrian crosswalks. The parallelogram-shaped pavement markings had a significant effect on reducing the vehicle–pedestrian crashes. Two crash prediction models were developed for vehicle–pedestrian crashes and rear-end crashes. According to the crash models, the presence of parallelogram-shaped pavement markings reduced vehicle–pedestrian crashes at pedestrian crosswalks by 24.87% with a 95% confidence interval of [10.06–30.78%]. However, the model results also showed that the presence of parallelogram-shaped pavement markings increased rear-end crashes at pedestrian crosswalks by 5.4% with a 95% confidence interval of [0–11.2%].

Keywords: Parallelogram-shaped pavement markings

AbstractObjective Describe age-based urban pedestrian versus auto crash characteristics and identify crash characteristics associated with injury severity. Materials and methods Secondary analysis of the 2004–2010 National Highway and Traffic Safety Administration database for Illinois. All persons in Chicago crashes with age data who were listed as pedestrians (n = 7175 child age ≤19 yo, n = 16,398 adult age ≥20 yo) were included. Incidence and crash characteristics were analyzed by age groups and year. Main outcome measures were incidence, crash setting, and injury severity. Multivariate logistic regression analysis was performed to estimate injury severity by crash characteristics. Results Overall incidence was higher for child (146.6 per 100,000) versus adult (117.3 per 100,000) pedestrians but case fatality rate was lower (0.7% for children, 1.7% for adults). Child but not adult pedestrian injury incidence declined over time (trend test p < 0.0001 for <5 yo, 5–9 yo, and 10–14 yo; p < 0.05 for 15–19 yo, p = 0.96 for ≥20 yo). Most crashes for both children and adults took place during optimal driving conditions. Injuries were more frequent during warmer months for younger age groups compared to older (χ2 p < 0.001). Midblock crashes increased as age decreased (p < 0.0001 for trend). Most crashes occurred at sites with sub-optimal traffic controls but varied by age (p < 0.0001 for trend). Crashes were more likely to be during daylight on dry roads in clear weather conditions for younger age groups compared to older (χ2 p < 0.001). Daylight was associated with less severe injury (child {OR} 0.93, 95% {CI} 0.87–0.98; adult {OR} 0.90, 95% {CI} 0.87–0.93). Conclusion The incidence of urban pedestrian crashes declined over time for child subgroups but not for adults. The setting of pedestrian crashes in Chicago today varies by age but is similar to that seen in other urban locales previously. Injuries for all age groups tend to be less severe during daylight conditions. Age-based prevention efforts may prove beneficial.

Keywords: Pedestrian injury

Abstract Fatality rates in Indian cities have increased manifolds in the recent years as cities continue to expand. The actual crash risk observed on different infrastructures is different and it depends upon the crash rate and the exposure on these infrastructures. This analysis uses crash data from police reported fatal crashes in the urban limits of the city to decide actual risk. The fatal crashes are accurately reported in police records, while minor and major crashes are under reported in India. The study considered risk to road users from six commonly used modes of transportation; walking, bicycling, riding motorized two- wheeler, auto-rickshaw, car, and bus. The perceived risk has derived for all these modes on different infrastructures; mid- block, signalized intersection, un-signalized intersection, and rotary intersection from household survey. This study examined the trend of fatal crashes and the relationship between actual and perceived crash risk on different infrastructures.

Keywords: Actual risk

Abstract A sufficient understanding of the safety impact of lane widths in urban areas is necessary to produce geometric designs that optimize safety performance for all users. The overarching trend found in the research literature is that as lane widths narrow, crash frequency increases. However, this trend is inconsistent and is the result of multiple cross-sectional studies that have issues related to lack of control for potential confounding variables, unobserved heterogeneity or omitted variable bias, or endogeneity among independent variables, among others. Using ten years of mid-block crash data on urban arterials and collectors from four cities in Nebraska, crash modification factors (CMFs) were estimated for various lane widths and crash types. These {CMFs} were developed using the propensity scores-potential outcomes methodology. This method reduces many of the issues associated with cross-sectional regression models when estimating the safety effects of infrastructure-related design features. Generalized boosting, a non-parametric modeling technique, was used to estimate the propensity scores. Matching was performed using both Nearest Neighbor and Mahalanobis matching techniques. {CMF} estimation was done using mixed-effects negative binomial or Poisson regression with the matched data. Lane widths included in the analysis included 9 ft, 10 ft, 11 ft, and 12 ft. Some of the estimated {CMFs} were point estimates while others were functions of traffic volume (i.e., the {CMF} changed depending on the traffic volume). Roadways with 10 ft travel lanes were found to experience the highest crash frequency relative to other lane widths. Meanwhile, roads with 9 ft travel lanes were found to experience the lowest relative crash frequency. While this may be due to increased driver caution when traveling on narrow lanes, it is possible that unobserved factors influenced this result. {CMFs} for target crash types (sideswipe same-direction and sideswipe opposite-direction) were consistent with the values currently used in the Highway Safety Manual (HSM).

Keywords: Lane width

Abstract Severe crashes are causing serious social and economic loss, and because of this, reducing crash injury severity has become one of the key objectives of the high speed facilities’ (freeway and expressway) management. Traditional crash injury severity analysis utilized data mainly from crash reports concerning the crash occurrence information, drivers’ characteristics and roadway geometric related variables. In this study, real-time traffic and weather data were introduced to analyze the crash injury severity. The space mean speeds captured by the Automatic Vehicle Identification (AVI) system on the two roadways were used as explanatory variables in this study; and data from a mountainous freeway (I-70 in Colorado) and an urban expressway (State Road 408 in Orlando) have been used to identify the analysis result's consistence. Binary probit (BP) models were estimated to classify the non-severe (property damage only) crashes and severe (injury and fatality) crashes. Firstly, Bayesian {BP} models’ results were compared to the results from Maximum Likelihood Estimation {BP} models and it was concluded that Bayesian inference was superior with more significant variables. Then different levels of hierarchical Bayesian {BP} models were developed with random effects accounting for the unobserved heterogeneity at segment level and crash individual level, respectively. Modeling results from both studied locations demonstrate that large variations of speed prior to the crash occurrence would increase the likelihood of severe crash occurrence. Moreover, with considering unobserved heterogeneity in the Bayesian {BP} models, the model goodness-of-fit has improved substantially. Finally, possible future applications of the model results and the hierarchical Bayesian probit models were discussed.

Keywords: Crash injury severity

Abstract This study set out to evaluate the effectiveness of low speed autonomous emergency braking (AEB) technology in current model passenger vehicles, based on real-world crash experience. The validating vehicle safety through meta-analysis (VVSMA) group comprising a collaboration of government, industry consumer organisations and researchers, pooled data from a number of countries using a standard analysis format and the established {MUND} approach. Induced exposure methods were adopted to control for any extraneous effects. The findings showed a 38 percent overall reduction in rear-end crashes for vehicles fitted with {AEB} compared to a comparison sample of similar vehicles. There was no statistical evidence of any difference in effect between urban (≤60 km/h) and rural (>60 km/h) speed zones. Areas requiring further research were identified and widespread fitment through the vehicle fleet is recommended.

Keywords: {AEB} technology

Powered Two-Wheelers are greatly represented in fatal crashes, above all in urban areas accounting for 21% of all road fatalities by mode of transport in EU. In an international comparison of {PTWs} crashes, Italy assumes a leadership accounting 30% of deaths on the total losses in crashes in urban area. In this paper a Bayesian approach is used to analyze proportion of {PTWs} fatal crashes with respect to total number involving a {PTW} in different urban areas in Italy. Proportion of fatalities is used as measure of severity risk which can be ranked in order to identify anomalous situations.

Keywords: Powered Two Wheelers

AbstractIntroduction Extent of secondary crashes derived from primary incidents involving abandoned and disabled vehicles are presented in this paper. Method Using years 2004 to 2010 incident and crash data on selected Tennessee freeways, the study identified secondary crashes that resulted from disabled and abandoned vehicle primary incidents. The relationship between time and distance gaps before the secondary crash with respect to individual incident characteristics were evaluated through descriptive statistics and linear regression. Results The time and distance gap analysis indicated that a large portion of secondary crashes occurred within 20 min after the primary incidents and within a distance of 0.5 miles upstream. While 76% of incidents involved shoulder, most secondary crashes were related to the closing of right lanes. Overall, 58% of the secondary crashes occurred within 30 min after the occurrence of the primary incidents. Most of the vehicles in the incidents that involved towing and caused secondary crashes were towed or removed out of the travel way within 60 min from the time of occurrence. The study found that most (95%) secondary crashes were property damage only (PDO), while 49% were rear-end crashes. The negative binomial model was used to evaluate the impact of roadway geometry and traffic factors associated with frequency of these secondary crashes. It was found that the posted speed limit, congested segments, segments with high percentages of trucks, and peak hour volumes increased the likelihood of secondary crash occurrence. Roadway segments with wider medians, shoulders, and multilanes decrease the likelihood of secondary crashes caused by abandoned and disabled vehicles as the primary incidents. Practical applications The paper recommends that wider shoulders be provided on any section of freeway to accommodate abandoned or disabled vehicles to avoid blocking of travel lane(s).

Keywords: Incident

Abstract The Highway Safety Manual (HSM) recommends using the empirical Bayes (EB) method with locally derived calibration factors to predict an agency’s safety performance. However, the data needs for deriving these local calibration factors are significant, requiring very detailed roadway characteristics information. Many of the data variables identified in the {HSM} are currently unavailable in the states’ databases. Moreover, the process of collecting and maintaining all the {HSM} data variables is cost-prohibitive. Prioritization of the variables based on their impact on crash predictions would, therefore, help to identify influential variables for which data could be collected and maintained for continued updates. This study aims to determine the impact of each independent variable identified in the {HSM} on crash predictions. A relatively recent data mining approach called boosted regression trees (BRT) is used to investigate the association between the variables and crash predictions. The {BRT} method can effectively handle different types of predictor variables, identify very complex and non-linear association among variables, and compute variable importance. Five years of crash data from 2008 to 2012 on two urban and suburban facility types, two-lane undivided arterials and four-lane divided arterials, were analyzed for estimating the influence of variables on crash predictions. Variables were found to exhibit non-linear and sometimes complex relationship to predicted crash counts. In addition, only a few variables were found to explain most of the variation in the crash data.

Keywords: Highway Safety Manual

Background Previous research has identified teenage drivers as having an increased risk for motor-vehicle crash injury compared with older drivers, and rural roads as having increased crash severity compared with urban roads. Few studies have examined incidence and characteristics of teen driver-involved crashes on rural and urban roads. Methods All crashes involving a driver aged 10 through 18 were identified from the Iowa Department of Transportation crash data from 2002 through 2008. Rates of overall crashes and fatal or severe injury crashes were calculated for urban, suburban, rural, and remote rural areas. The distribution of driver and crash characteristics were compared between rural and urban crashes. Logistic regression was used to identify driver and crash characteristics associated with increased odds of fatal or severe injury among urban and rural crashes. Results For younger teen drivers (age 10 through 15), overall crash rates were higher for more rural areas, although for older teen drivers (age 16 through 18) the overall crash rates were lower for rural areas. Rural teen crashes were nearly five times more likely to lead to a fatal or severe injury crash than urban teen crashes. Rural crashes were more likely to involve single vehicles, be late at night, involve a failure to yield the right-of-way and crossing the center divider. Conclusions Intervention programs to increase safe teen driving in rural areas need to address specific risk factors associated with rural roadways. Impact on Industry Teen crashes cause lost work time for teen workers as well as their parents. Industries such as safety, health care, and insurance have a vested interest in enhanced vehicle safety, and these efforts should address risks and injury differentials in urban and rural roadways.

Keywords: Adolescent health

Abstract Traffic safety on urban arterials is influenced by several key variables including geometric design features, land use, traffic volume, and travel speeds. This paper is an exploratory study of the relationship of these variables to safety. It uses a comparatively new method of measuring speeds by extracting {GPS} data from taxis operating on Shanghai’s urban network. This {GPS} derived speed data, hereafter called Floating Car Data (FCD) was used to calculate average speeds during peak and off-peak hours, and was acquired from samples of 15,000+ taxis traveling on 176 segments over 18 major arterials in central Shanghai. Geometric design features of these arterials and surrounding land use characteristics were obtained by field investigation, and crash data was obtained from police reports. Bayesian inference using four different models, Poisson-lognormal (PLN), {PLN} with Maximum Likelihood priors (PLN-ML), hierarchical {PLN} (HPLN), and {HPLN} with Maximum Likelihood priors (HPLN-ML), was used to estimate crash frequencies. Results showed the HPLN-ML models had the best goodness-of-fit and efficiency, and models with {ML} priors yielded estimates with the lowest standard errors. Crash frequencies increased with increases in traffic volume. Higher average speeds were associated with higher crash frequencies during peak periods, but not during off-peak periods. Several geometric design features including average segment length of arterial, number of lanes, presence of non-motorized lanes, number of access points, and commercial land use, were positively related to crash frequencies.

Keywords: Urban arterial

AbstractIntroduction Contributory factors to motorcycle crashes vary among populations depending on several aspects such as the users' profiles, the composition and density of traffic, and the infrastructure features. A better understanding of local motorcycle crashes can be reached in those places where a comprehensive analysis is performed. This paper presents the results obtained from a case study analysis of 400 police records of accidents involving motorcycles in Bogota. Method To achieve a deeper level of understanding of how these accidents occur, we propose a systemic approach that uses available crash data. The methodology is inspired by accident prototypical scenarios, a tool for analysis developed in France. Results When grouping cases we identified three categories: solo motorcycle accidents, motorcyclist and pedestrian accidents, and accidents involving a motorcycle and another vehicle. Within these categories we undertook in-depth analyses of 32 groups of accidents obtaining valuable information to better comprehend motorcyclists' road crashes in a local context. Recurrent contributory factors in the groups of accidents include: inexperienced motorcyclists, wide urban roads that incite speeding and risky overtaking maneuvers, flowing urban roads that encourage high speed and increased interaction between vehicles, and lack of infrastructure maintenance. Practical Applications The results obtained are a valuable asset to define measures that will be conveniently adapted to the group of accident on which we want to act. The methodology exposed in this paper is applicable to the study of road crashes that involve all types of actors, not only the motorcyclists, and in contexts different than those presented in Bogota.

Keywords: Motorcyclist

This research examines a case-control (N = 305) for {CVC} (car versus car) and {CVM} (car versus motorcycle) crashes from the New Zealand drawing from the 2004 to 2009 police reports entered into the Crash Analysis Systems (CASs) database. The characteristics of the crashes are compared across the vehicle configurations to distinguish the features of {CVM} crashes. The analyses show that CVM-type crashes are not easily distinguished from CVC-type crashes. The two crash types are similar, contrary to overseas recent findings but consistent with those reported nearly 20 years ago by Cercarelli, Arnold, Rosman, Sleet, and Thornett (1992). Four exceptions are that CVM-type crashes occur more often than expected in urban speed zones, between the times of 4–7 pm, and at uncontrolled intersections. {CVM} crashes occur less often in merging traffic. These findings are discussed in the context of the conspicuity hypothesis that posits that crashes with motorcycles occur more frequently because they are harder to detect.

Keywords: Motorcycles

Abstract Crash data are collected through police reports and integrated with road inventory data for further analysis. Integrated police reports and inventory data yield correlated multivariate data for roadway entities (e.g., segments or intersections). Analysis of such data reveals important relationships that can help focus on high-risk situations and coming up with safety countermeasures. To understand relationships between crash frequencies and associated variables, while taking full advantage of the available data, multivariate random-parameters models are appropriate since they can simultaneously consider the correlation among the specific crash types and account for unobserved heterogeneity. However, a key issue that arises with correlated multivariate data is the number of crash-free samples increases, as crash counts have many categories. In this paper, we describe a multivariate random-parameters zero-inflated negative binomial (MRZINB) regression model for jointly modeling crash counts. The full Bayesian method is employed to estimate the model parameters. Crash frequencies at urban signalized intersections in Tennessee are analyzed. The paper investigates the performance of {MZINB} and {MRZINB} regression models in establishing the relationship between crash frequencies, pavement conditions, traffic factors, and geometric design features of roadway intersections. Compared to the {MZINB} model, the {MRZINB} model identifies additional statistically significant factors and provides better goodness of fit in developing the relationships. The empirical results show that {MRZINB} model possesses most of the desirable statistical properties in terms of its ability to accommodate unobserved heterogeneity and excess zero counts in correlated data. Notably, in the random-parameters {MZINB} model, the estimated parameters vary significantly across intersections for different crash types.

Keywords: Crash frequency

AbstractObjective To estimate the incidence and risk of medically or police attended bicycle crashes in a prospective cohort study in New Zealand. Method The Taupo Bicycle Study involved 2590 adult cyclists recruited from the country's largest cycling event in 2006 and followed over a median period of 4.6 years through linkage to four administrative databases. Incidence rates with Poisson distribution confidence intervals were computed and Cox regression modelling for repeated events was performed. Results The 66 on-road crashes and 10 collisions per 1000 person-years corresponded to 240 crashes and 38 collisions per million hours spent road cycling. The risk increased by 6% and 8% respectively for an extra cycling hour each week. There were 50 off-road crashes per 1000 person-years. Residing in urban areas and in Auckland (region with the lowest level of cycling), riding in a bunch, using a road bike and experiencing a previous crash predicted a higher risk. Habitual use of conspicuity aids appeared to lower the risk. Conclusion The risk is higher in urban areas and where cycling is less common, and increased by bunch riding and previous crashes. These findings alongside the possible protective effect of conspicuity aids suggest promising approaches to improving cycle safety.

Keywords: Bicycling

Abstract Urban expressways play a vital role in the modern mega cities by serving peak hour traffic alongside reducing travel time for moderate to long distance intra-city trips. Thus, ensuring safety on these roads holds high priority. Little knowledge has been acquired till date regarding crash mechanism on these roads. This study uses high-resolution traffic data collected from the detectors to identify factors influencing crash. It also identifies traffic patterns associated with different types of crashes and explains crash phenomena thereby. Unlike most of the previous studies on conventional expressways, the research separately investigates the basic freeway segments (BFS) and the ramp areas. The study employs random multinomial logit, a random forest of logit models, to rank the variables; expectation maximization clustering algorithm to identify crash prone traffic patterns and classification and regression trees to explain crash phenomena. As accentuated by the study outcome, crash mechanism is not generic throughout the expressway and it varies from the {BFS} to the ramp vicinities. The level of congestion and speed difference between upstream and downstream traffic best explains crashes and their types for the BFS, whereas, the ramp flow has the highest influence in determining the types of crashes within the ramp vicinities. The paper also discusses about the applicability of different countermeasures, such as, variable speed limits, temporary restriction on lane changing, posting warnings, etc., to attenuate different patterns of hazardous traffic conditions. The study outcome can be utilized in designing location and traffic condition specific proactive road safety management systems for urban expressways.

Keywords: Urban expressway

Abstract Since a crash modification factor (CMF) represents the overall safety performance of specific treatments in a single fixed value, there is a need to explore the variation of {CMFs} with different roadway characteristics among treated sites over time. Therefore, in this study, we (1) evaluate the safety performance of a sample of urban four-lane roadway segments that have been widened with one through lane in each direction and (2) determine the relationship between the safety effects and different roadway characteristics over time. Observational before–after analysis with the empirical Bayes (EB) method was assessed in this study to evaluate the safety effects of widening urban four-lane roadways to six-lanes. Moreover, the nonlinearizing link functions were utilized to achieve better performance of crash modification functions (CMFunctions). The {CMFunctions} were developed using a Bayesian regression method including the estimated nonlinearizing link function to incorporate the changes in safety effects of the treatment over time. Data was collected for urban arterials in Florida, and the Florida-specific full {SPFs} were developed and used for {EB} estimation. The results indicated that the conversion of four-lane roadways to six-lane roadways resulted in a crash reduction of 15 percent for total crashes, and 24 percent for injury crashes on urban roadways. The results show that the safety effects vary across the sites with different roadway characteristics. In particular, {LOS} changes, time changes, and shoulder widths are significant parameters that affect the variation of CMFs. Moreover, it was found that narrowing shoulder and median widths to make space for an extra through lane shows a negative safety impact. It was also found that including the nonlinearizing link functions in developing {CMFunctions} shows more reliable estimates, if the variation of {CMFs} with specific parameters has a nonlinear relationship. The findings provide insights into the selection of roadway sites for adding through lanes.

Keywords: Safety effectiveness

Abstract This paper proposes an estimation approach for count data models with endogenous covariates. The maximum approximate composite marginal likelihood inference approach is used to estimate model parameters. The modeling framework is applied to predict crash frequency at urban intersections in Irving, Texas. The sample is drawn from the Texas Department of Transportation (TxDOT) crash incident files for the year 2008. The results highlight the importance of accommodating endogeneity effects in count models. In addition, the results reveal the increased propensity for crashes at intersections with flashing lights, intersections with crest approaches, and intersections that are on frontage roads.

Keywords: Count data

Abstract Many urban designers and researchers argue that walkable urban environments can encourage older residents’ walking activities that benefit their physical health. However, walking also exposes older adults to safety risks, including due to traffic accidents. This study seeks to reveal the interactions between urban form and safety affecting urban baby boomers’ walking behavior. Spatial analysis reveals traffic collision patterns in urban Boston neighborhoods, detecting hotspots around activity centers. Structural equation modeling, estimated on individual data collected from a mail-back survey and utilizing numerous measures of neighborhood urban form and accessibility, then attempts to reveal the causal, interacting relationships between neighborhood-level urban form, traffic crashes, and baby boomers’ walking behavior. The analysis identifies significant effects of walkable urban forms (e.g., mixed use, well-connected streets, and good access to potential destinations) on older adults’ walking. Yet, accessibility to retail, as well as traffic speed and volume, are positively associated with the traffic collision frequency. The results suggest more cautious approaches may be necessary for designing urban spaces for walkability and also call into question prescriptions based on the “safety in numbers” hypothesis.

Keywords: Older pedestrians

Abstract Using motorcycle crash data for Iowa from 2001 to 2008, this paper estimates a mixed logit model to investigate the factors that affect crash severity outcomes in a collision between a motorcycle and another vehicle. These include crash-specific factors (such as manner of collision, motorcycle rider and non-motorcycle driver and vehicle actions), roadway and environmental conditions, location and time, motorcycle rider and non-motorcycle driver and vehicle attributes. The methodological approach allows the parameters to vary across observations as opposed to a single parameter representing all observations. Our results showed non-uniform effects of rear-end collisions on minor injury crashes, as well as of the roadway speed limit greater or equal to 55 mph, the type of area (urban), the riding season (summer) and motorcyclist's gender on low severity crashes. We also found significant effects of the roadway surface condition, clear vision (not obscured by moving vehicles, trees, buildings, or other), light conditions, speed limit, and helmet use on severe injury outcomes.

Keywords: Motorcycle safety

Abstract Urban intersections crashes cause significant economic loss. The safety management process undertaken by most states in the United States is referred to as Highway Safety Improvement Program and consists of three standardized steps: (i) identification of critical crash locations, (ii) development of countermeasures, and (iii) resource allocation among identified crash locations. Often these three steps are undertaken independently, with limited detail of each step at the state planning agencies. The literature review underlines the importance of the third step, and the lack of sophisticated tools available to state planning agencies for leveraging information obtained from the first two steps. Further, non-strategic approaches and unavailability of methods for evaluating policies may lead to sub-optimal funding allocation. This paper overcomes these limitations and proposes multiple optimal resource allocation strategies for improvements at urban intersections that maximize safety benefits, under budget and policy constraints. Proposed policy measures based on benefits maximization (economic competitiveness), equitable allocation (equity), and relaxation of mutually exclusiveness (multiple alternatives at one location) produce significantly different alternative and fund allocation. The proposed models are applied to selected intersections in four counties of southeast Michigan. Results reinforce the applicability of the strategies/policies and tools developed in this paper for safety project funding allocation on critical urban intersections.

Keywords: Resource allocation

Abstract Conventional crash frequency models rely on an assumption of independence among observed crashes. However, this assumption is frequently proved false by spatially related crash observations, particularly for intersection crashes observed in high-density road networks. Crash frequency models that ignore the hierarchy and spatial correlation of closely spaced intersections can lead to biased estimations. As a follow-up to our previous paper (Xie et al., 2013), this study aims to address this issue by introducing an improved crash frequency model. Data for 195 signalized intersections along 22 corridors in the urban areas of Shanghai was collected. Moran׳s I statistic of the crash data confirmed the spatial dependence of crash occurrence among the neighboring intersections. Moreover, Lagrange Multiplier test was performed and it suggested that the spatial dependence should be captured in the model error term. A hierarchical model incorporating a conditional autoregressive (CAR) effect term for the spatial correlation was developed in the Bayesian framework. A deviance information criterion (DIC) and cross-validation test were used for model selection and comparison. The results showed that the proposed model outperformed traditional models in terms of the overall goodness of fit and predictive performance. In addition, the significance of the corridor-specific random effect and {CAR} effect revealed strong evidence for the presence of heterogeneity across corridors and spatial correlation among intersections.

Keywords: Crash frequency model

As automobile transportation continues to increase around the world, bicyclists, pedestrians, and motorcyclists, also known as vulnerable road users (VRUs), will become more susceptible to traffic crashes, especially in countries where traffic laws are poorly enforced. Many countries, however, are employing innovative strategies to ensure that road users can more safely navigate the urban landscape. While bicyclists and motorcyclists are important road users, this paper will focus on pedestrian crash problems and solutions. Pedestrians are most at risk in urban areas due in part to the large amount of pedestrian and vehicle activity in urban areas. With this in mind, designing safe, accessible, and comprehensive facilities for pedestrians is vital to reducing pedestrian crashes. This paper will provide some insight into the magnitude of the pedestrian crash problem around the world, and will offer some lessons learned from several countries, particularly in Europe and the U.S., for improving pedestrian safety. Beginning with pedestrian safety statistics at the global, regional, and national levels, this paper will address potential countermeasures and strategies for improving pedestrian safety from an international perspective.

Keywords: Pedestrian safety

Abstract Each year aviation disasters occur around the world, leading to significant human and economic losses, environmental damage, and property destruction. Consequently, airplane crash hazards are often taken into consideration when developing disaster and emergency management plans. This is particularly the case in urban areas. Unlike other types of hazards in urban areas such as flooding, earthquake, rail and roads, there is no hazard and risk maps for air transportation. This paper presents the results of a study conducted to develop the basis for a simple and new airplane hazard and risk mapping approach that utilizes flight path data to produce airplane hazard maps at local, regional, and national scales. We have applied this method to develop hazard maps for the Greater Toronto Area (GTA), Canada using flight paths to and from Pearson International Airport.

Keywords: Air transportation hazard

Background Most previous literature on urban/rural differences in road crashes has a primary focus on severe injuries or deaths, which may be largely explained by variations of medical resources. Little has been reported on police-reported crashes by geographical location, or crash type and severity, especially among young drivers. Methods {DRIVE} is a prospective cohort study of 20,822 drivers aged 17–24 in NSW, Australia. Information on risk factors was collected via online questionnaire and subsequently linked to police-reported crashes. Poisson regression was used to analyse risk of various crash types by three levels of rurality of residence: urban, regional (country towns and surrounds) and rural. Results Compared to urban drivers, risk of crash decreased with increasing rurality (regional adjusted RR: 0.7, 95% {CI} 0.6–0.9; rural adjusted RR: 0.5, 95% {CI} 0.3–0.7). Among those who crashed, risk of injurious crash did not differ by geographic location; however, regional and rural drivers had significantly higher risk of a single versus multiple vehicle crash (regional adjusted {RR} 1.8, 95% {CI} 1.3–2.5; rural adjusted RR: 2.0, 95% {CI} 1.1–3.6), which was explained by speeding involvement and road alignment at the time or site of crash. Conclusions Although young urban drivers have a higher crash risk overall, rural and regional residents have increased risk of a single vehicle crash. Interventions to reduce single vehicle crashes should aim to address key issues affecting such crashes, including speeding and specific aspects of road geometry.

Keywords: Young driver

Abstract The influence of intersection features on safety has been examined extensively because intersections experience a relatively large proportion of motor vehicle conflicts and crashes. Although there are distinct differences between passenger cars and large trucks-size, operating characteristics, dimensions, and weight-modeling crash counts across vehicle types is rarely addressed. This paper develops and presents a multivariate regression model of crash frequencies by collision vehicle type using crash data for urban signalized intersections in Tennessee. In addition, the performance of univariate Poisson-lognormal (UVPLN), multivariate Poisson (MVP), and multivariate Poisson-lognormal (MVPLN) regression models in establishing the relationship between crashes, traffic factors, and geometric design of roadway intersections is investigated. Bayesian methods are used to estimate the unknown parameters of these models. The evaluation results suggest that the {MVPLN} model possesses most of the desirable statistical properties in developing the relationships. Compared to the {UVPLN} and {MVP} models, the {MVPLN} model better identifies significant factors and predicts crash frequencies. The findings suggest that traffic volume, truck percentage, lighting condition, and intersection angle significantly affect intersection safety. Important differences in car, car–truck, and truck crash frequencies with respect to various risk factors were found to exist between models. The paper provides some new or more comprehensive observations that have not been covered in previous studies.

Keywords: Crash frequency

Knowledge of the factors that contribute to pedestrian crashes is fundamental to the design of engineering, enforcement and education measures to decrease the number and severity of these crashes. To identify the factors that contribute to pedestrian crashes on rural highways crossing urban areas in the Federal District, Brazil, an investigatory procedure was developed. The procedure was implemented by the Federal District Road Department (DER–DF) for a period of 6 months. This study presents the investigatory method and the results. Data analysis indicated the importance of conducting detailed studies of the factors that contribute to pedestrian crashes. The main contributory factors identified are presented and discussed.

Keywords: Pedestrians

AbstractIntroduction This study examined the crash causative factors of signalized intersections under mixed traffic using advanced statistical models. Method Hierarchical Poisson regression and logistic regression models were developed to predict the crash frequency and severity of signalized intersection approaches. The prediction models helped to develop general safety countermeasures for signalized intersections. Results The study shows that exclusive left turn lanes and countdown timers are beneficial for improving the safety of signalized intersections. Safety is also influenced by the presence of a surveillance camera, green time, median width, traffic volume, and proportion of two wheelers in the traffic stream. The factors that influence the severity of crashes were also identified in this study. Practical application As a practical application, the safe values of deviation of green time provided from design green time, with varying traffic volume, is presented in this study. This is a useful tool for setting the appropriate green time for a signalized intersection approach with variations in the traffic volume.

Keywords: Signal control

Pedestrian fatalities account for approximately 12% of all fatalities statewide in Texas and as much as 18% in urban area. Locating where the high risk spot is and addressing the cause factors are critical. North Lamar Boulevard in Austin Texas has seen an increase in pedestrian crashes in recent years. A team of agencies collaborated on ways to address the safety concern. After studying the crash locations and pedestrian crossing data, the group identified two study sections. The crashes historical records provide the opportunity to access the massive crash data and associated crash attributes. Geographic Information System (GIS) technology was used to facilitate the data collection and the {GIS} map overlaid with road network was used in the case study corridor. The countermeasure for the pedestrian crash was analyzed and proposed at the end.

Keywords: pedestrian safety

Analysis of both the crash count and the severity of injury are required to provide the complete picture of the safety situation of any given roadway. The randomness of crashes, the one-way dependency of injury on crash occurrence and the difference in response types have typically led researchers into developing independent statistical models for crash count and severity classification. The Genetic Programming (GP) methodology adopts the concepts of evolutionary biology such as crossover and mutation in effectively giving a common heuristic approach to model the development for the two different modeling objectives. The chosen {GP} models have the highest hit rate for rear-end crash classification problem and the least error for function fitting (regression) problems. Higher Average Daily Traffic (ADT) is more likely to result in more crashes. Absence of on-street parking may result in diminished severity of injuries resulting from crashes as they may provide “soft” crash barrier in contrast to fixed road side objects. Graphical presentation of the frequency of crashes with varying input variables shed new light on the results and its interpretation. Higher friction coefficient of roadways result in reduced frequency of crashes during the morning peak hours, with the trend being reversed during the afternoon peak hours. Crash counts have been observed to be at a maximum at a surface width of 30 ft. Sensitivity analysis results reflect that {ADT} is responsible for the largest variation in crash counts on urban arterials.

Keywords: Arterial safety

Abstract Full Bayesian (FB) before–after evaluation is a newer approach than the empirical Bayesian (EB) evaluation in traffic safety research. While a number of earlier studies have conducted univariate and multivariate {FB} before–after safety evaluations and compared the results with the {EB} method, often contradictory conclusions have been drawn. To this end, the objectives of the current study were to (i) perform a before–after safety evaluation using both the univariate and multivariate {FB} methods in order to enhance our understanding of these methodologies, (ii) perform the {EB} evaluation and compare the results with those of the {FB} methods and (iii) apply the {FB} and {EB} methods to evaluate the safety effects of reducing the urban residential posted speed limit (PSL) for policy recommendation. In addition to three years of crash data for both the before and after periods, traffic volume, road geometry and other relevant data for both the treated and reference sites were collected and used. According to the model goodness-of-fit criteria, the current study found that the multivariate {FB} model for crash severities outperformed the univariate {FB} models. Moreover, in terms of statistical significance of the safety effects, the {EB} and {FB} methods led to opposite conclusions when the safety effects were relatively small with high standard deviation. Therefore, caution should be taken in drawing conclusions from the {EB} method. Based on the {FB} method, the {PSL} reduction was found effective in reducing crashes of all severities and thus is recommended for improving safety on urban residential collector roads.

Keywords: Full Bayesian evaluation

Abstract In recent years, Bayesian random effect models that account for the temporal and spatial correlations of crash data became popular in traffic safety research. This study employs random effect Poisson Log-Normal models for crash risk hotspot identification. Both the temporal and spatial correlations of crash data were considered. Potential for Safety Improvement (PSI) were adopted as a measure of the crash risk. Using the fatal and injury crashes that occurred on urban 4-lane divided arterials from 2006 to 2009 in the Central Florida area, the random effect approaches were compared to the traditional Empirical Bayesian (EB) method and the conventional Bayesian Poisson Log-Normal model. A series of method examination tests were conducted to evaluate the performance of different approaches. These tests include the previously developed site consistence test, method consistence test, total rank difference test, and the modified total score test, as well as the newly proposed total safety performance measure difference test. Results show that the Bayesian Poisson model accounting for both temporal and spatial random effects (PTSRE) outperforms the model that with only temporal random effect, and both are superior to the conventional Poisson Log-Normal model (PLN) and the {EB} model in the fitting of crash data. Additionally, the method evaluation tests indicate that the {PTSRE} model is significantly superior to the {PLN} model and the {EB} model in consistently identifying hotspots during successive time periods. The results suggest that the {PTSRE} model is a superior alternative for road site crash risk hotspot identification.

Keywords: Hotspot identification

Introduction Studies have demonstrated that the fatality risk for motor vehicle crashes (MVCs) is higher in rural than urban areas. The purpose of this study was to quantify the risk of a fatal outcome associated with a crash by the urban/rural classification of the driver's county of residence and the county of crash before and after adjusting for potentially confounding factors. Methods County of crash and driver's county of residence were classified as urban or rural for 514,648 Utah crash participants. Multivariate regression analysis was used to assess the impact of rural versus urban crash location on fatality outcomes for both urban and rural drivers. Results Before adjusting for confounding factors the relative risk of fatality in a rural versus urban crash was 9.7 (95% CI: 8.0–11.7) for urban drivers and their passengers compared to 1.8 (95% CI: 1.3–2.6) for rural residents. Adjustment for behavioral, road, and crash characteristics reduced risk estimates to 2.8 (95% CI: 2.2–3.5) and 1.2 (95% CI: 0.8–1.7), respectively. Conclusion Urban and rural drivers may have distinct risk factors for {MVC} fatality in rural areas. Interventions to reduce the risk of fatality in rural areas should evaluate the needs of both urban and rural drivers.

Keywords: Fatality

Abstract A nine-year (1999–2007) continuous panel of crash histories on interstates in Washington State, USA, was used to estimate random parameter negative binomial (RPNB) models for various aggregations of crashes. A total of 21 different models were assessed in terms of four ways to aggregate crashes, by: (a) severity, (b) number of vehicles involved, (c) crash type, and by (d) location characteristics. The models within these aggregations include specifications for all severities (property damage only, possible injury, evident injury, disabling injury, and fatality), number of vehicles involved (one-vehicle to five-or-more-vehicle), crash type (sideswipe, same direction, overturn, head-on, fixed object, rear-end, and other), and location types (urban interchange, rural interchange, urban non-interchange, rural non-interchange). A total of 1153 directional road segments comprising of the seven Washington State interstates were analyzed, yielding statistical models of crash frequency based on 10,377 observations. These results suggest that in general there was a significant improvement in log-likelihood when using {RPNB} compared to a fixed parameter negative binomial baseline model. Heterogeneity effects are most noticeable for lighting type, road curvature, and traffic volume (ADT). Median lighting or right-side lighting are linked to increased crash frequencies in many models for more than half of the road segments compared to both-sides lighting. Both-sides lighting thereby appears to generally lead to a safety improvement. Traffic volume has a random parameter but the effect is always toward increasing crash frequencies as expected. However that the effect is random shows that the effect of traffic volume on crash frequency is complex and varies by road segment. The number of lanes has a random parameter effect only in the interchange type models. The results show that road segment-specific insights into crash frequency occurrence can lead to improved design policy and project prioritization.

Keywords: Crash frequency aggregations

Abstract In this paper, we evaluated the effects on speed and safety of the point-to-point (P2P) speed enforcement system activated on the urban motorway {A56} in Italy. The {P2P} speed enforcement is a relatively new approach to traffic law enforcement that involves the calculation of the average speed over a section. To evaluate the speed effects, we performed a before–after analysis of speed data investigating also effects on non-compliance to speed limits. To evaluate the safety effects, we carried out an empirical Bayes observational before-and-after study. The {P2P} system led to very positive effects on both speed and safety. As far as the effects on the section average travel speeds, the system yielded to a reduction in the mean speed, the 85th percentile speed, the standard deviation of speed, and the proportion of drivers exceeding the speed limits, exceeding the speed limits more than 10 km/h, and exceeding the speed limits more than 20 km/h. The best results were the decrease of the speed variability and the reduction of the excessive speeding behaviour. The decrease in the standard deviation of speed was 26% while the proportion of light and heavy vehicles exceeding the speed limits more than 20 km/h was reduced respectively by 84 and 77%. As far as the safety effects, the {P2P} system yielded to a 32% reduction in the total crashes, with a lower 95% confidence limit of the estimate equal to 22%. The greatest crash reductions were in rainy weather (57%), on wet pavement (51%), on curves (49%), for single vehicle crashes (44%), and for injury crashes (37%). It is noteworthy that the system produced a statistically significant reduction of 21% in total crashes also in the part of the motorway where it was not activated, thus generating a significant spillover effect. The investigation of the effects of the {P2P} system on speed and safety over time allowed to develop crash modification functions where the relationship between crash modification factors and speed parameters (mean speed, 85th percentile speed, and standard deviation of speed) was expressed by a power function. Crash modification functions show that the effect of speed on safety is greater on curves and for injury crashes. Even though the study results show excellent outcomes, we must point out that the crash reduction effects decreased over time and speed, speed variability, and non-compliance to speed limits significantly increased over time. To maintain its effectiveness over time, {P2P} speed enforcement must be actively managed, i.e. constantly monitored and supported by appropriate sanctions.

Keywords: Highway safety

Abstract The objectives of this manuscript are (1) to evaluate the effectiveness of on-street bicycle lane in reducing crashes involving bicyclists on urban roads, (2) to quantify and compare risk to bicyclists on road segments with and without on-street bicycle lane, (3) to evaluate the effect of on-street bicycle lane on other road network users (all crashes), and, (4) to assess the role of on-network characteristics (speed limit, the number of lanes, the width of on-street bicycle lane, the width of the right-most travel lane, and, the numbers of driveways, unsignalized approaches and signalized intersections per unit distance) on risk to bicyclists. Data for thirty-six segments with on-street bicycle lane and twenty-six segments without on-street bicycle lane in the city of Charlotte, North Carolina were extracted to compute and compare measures such as the number of bicycle crashes per center-lane mile, the number of bicycle crashes per annual million vehicle miles traveled (MVMT), the number of all crashes per center-lane mile, and the number of all crashes per MVMT. The results obtained from analysis indicate that bicyclists are three to four times at higher risk (based on traffic conditions) on segments without on-street bicycle lane than when compared to segments with on-street bicycle lane. An analysis conducted considering all crashes showed that on-street bicycle lanes do not have a statistically significant negative effect on overall safety. An increase in annual {MVMT} (exposure) and the number of signalized intersections per mile increases the number of bicycle crashes, while an increase in on-street bicycle lane width or right-most travel lane width (if on-street bicycle lane cannot be provided) decreases the number of bicycle crashes. Installing wider on-street bicycle lanes, limiting driveways to less than 50 per mile and unsignalized approaches to less than 10 per mile, increasing spacing between signalized intersections, and, facilitating wider right-most travel lane if on-street bicycle lane cannot be provided reduces occurrence of bicycle crashes and lowers risk to bicyclists on roads.

Keywords: Bicycle

Motorcycle riders would be more vulnerable in the event of a crash because of their lack of protection which would often result in them suffering more severe injuries than car drivers. This paper estimated three crash severity models to identify factors that contributed to increasing the severity of motorcycle involved crashes in the Canadian City of Calgary. We found that results from the ordered logit model, heterogeneous choice model and partially constrained generalized ordered logit model produced estimates that were very similar which attested to their robustness. Injury severity tended to increase in neighborhoods with loops and lollipops types of streets or involved right-angle and left-turn-across-path crashes, a truck, unsafe speed or alcohol use but tended to decrease if the crash occurred in parking lots or during winter, involved a van or male rider, or a rider following-too-closely to the vehicle in front.

Keywords: Motorcycles

Abstract The advent of Big Data era has transformed the outlook of numerous fields in science and engineering. The transportation arena also has great expectations of taking the advantage of Big Data enabled by the popularization of Intelligent Transportation Systems (ITS). In this study, the viability of a proactive real-time traffic monitoring strategy evaluating operation and safety simultaneously was explored. The objective is to improve the system performance of urban expressways by reducing congestion and crash risk. In particular, Microwave Vehicle Detection System (MVDS) deployed on an expressway network in Orlando was utilized to achieve the objectives. The system consisting of 275 detectors covers 75 miles of the expressway network, with average spacing less than 1 mile. Comprehensive traffic flow parameters per lane are continuously archived on one-minute interval basis. The scale of the network, dense deployment of detection system, richness of information and continuous collection turn {MVDS} as the ideal source of Big Data. It was found that congestion on urban expressways was highly localized and time-specific. As expected, the morning and evening peak hours were the most congested time periods. The results of congestion evaluation encouraged real-time safety analysis to unveil the effects of traffic dynamics on crash occurrence. Data mining (random forest) and Bayesian inference techniques were implemented in real-time crash prediction models. The identified effects, both indirect (peak hour, higher volume and lower speed upstream of crash locations) and direct (higher congestion index downstream to crash locations) congestion indicators confirmed the significant impact of congestion on rear-end crash likelihood. As a response, reliability analysis was introduced to determine the appropriate time to trigger safety warnings according to the congestion intensity. Findings of this paper demonstrate the importance to jointly monitor and improve traffic operation and safety. The Big Data generated by the {ITS} systems is worth further exploration to bring all their full potential for more proactive traffic management.

Keywords: Big Data

Speed limits were increased in Utah and other States after repeal of the national maximum speed limit law (NMSL) in 1995. This study analyzed effects of the increased speed limit on Utah highways on crash rates, fatality crash rates, and injury crash rates. Annual (1992–1999) rates of crashes, fatality crashes, and injury crashes for the following highway categories were calculated: urban Interstate segments (current speed limit 60–65 miles per hour (mph)); rural Interstate segments (current speed limit 70–75 mph); 55 mph rural non-Interstate highway segments; and high-speed non-Interstate highways (current speed limit 60–65 mph). Data were analyzed using autoregressive integrative moving average intervention time series analysis techniques. There were significant increases in total crash rates on urban (60–65 mph) Interstate segments (confounded by extensive ongoing highway construction on these highways), and in fatal crash rates on high-speed (60–65 mph) rural non-Interstate segments. The following variables were unaffected: total, fatality, and injury crash rates on rural Interstate segments; fatality and injury crash rates on urban Interstate segments; total and injury crash rates on high-speed non-Interstate segments. These results show an adverse effect on crash occurrence for subsets of crash types and highways, but do not show a major overall effect of {NMSL} repeal and increased speed limit on crash occurrence on Utah highways.

Keywords: Crashes

Urban arterials by their nature carry heavy traffic volumes and generate large numbers of motor vehicle crashes. The present study involved review of police crash reports to identify precrash events and driver actions for a sample of crashes on urban arterials and describes a method for reducing such crashes based on analyses of collision patterns and identification of locations with excessive numbers of crashes of a particular type. Police-reported crash data were obtained for three urban arterials in the Washington, {DC} metropolitan area. A total of 2013 crash reports were analyzed. Seven crash types accounted for nearly 90% of these reports. On each arterial studied, several locations with excessive numbers of crashes of a particular type were identified, and corresponding engineering countermeasures were recommended. Differences between the approach employed in this study and traditional blackspot analyses are discussed.

Keywords: Urban arterials

Abstract Previous studies have looked at different factors that contribute to large truck-involved crashes, however a detailed analysis considering the specific effects of time of day is lacking. Using the Crash Records Information System (CRIS) database in Texas, large truck-involved crashes occurring on urban freeways between 2006 and 2010 were separated into five time periods (i.e., early morning, morning, mid-day, afternoon and evening). A series of log likelihood ratio tests were conducted to validate that five separate random parameters logit models by time of day were warranted. The outcomes of each time of day model show major differences in both the combination of variables included in each model and the magnitude of impact of those variables. These differences show that the different time periods do in fact have different contributing factors to each injury severity further highlighting the importance of examining crashes based on time of day. Traffic flow, light conditions, surface conditions, time of year and percentage of trucks on the road were found as key differences between the time periods.

Keywords: Truck accidents

AbstractIntroduction The population-based rate of motor vehicle crash mortality is consistently higher in rural locations, but it is unclear how much of this disparity might be due to geographic barriers or deficiencies in emergency medical services (EMS). We sought to analyze separately factors associated with the occurrence of a severe injury and those associated with death after injury had occurred. Methods Data from all police-reported crashes in 11 states from 2005–2007 were obtained through the National Highway Traffic Safety Administration (NHTSA) State Data System (SDS). Logistic regression was used to estimate factors associated with (1) death; (2) severe (incapacitating or fatal) injury; and (3) death given severe injury. Models included covariates related to the person, vehicle, and event; county location was specified using Rural–Urban Continuum Codes (RUCC). Results Older age, not wearing a belt, ejection, alcohol involvement, high speed, and early morning times were associated with increased risk of both severe injury and death. Controlling for these factors, and restricting analysis to persons who had suffered a severe injury, the adjusted odds ratio (aOR) associated with death was higher for counties classified rural (RUCC 6–7, aOR 1.23, 95% {CI} 1.16–1.31) or very rural (RUCC 8–9, aOR 1.31, 95% {CI} 1.18–1.46). Conclusions Persons severely injured in crashes are more likely to die if they are in rural locations, possibly due to {EMS} constraints. As NHTSA-SDS data become more available and more uniform, they may be useful to explore specific factors contributing to this increased risk.

Keywords: Crash

It is well known from the literature that road lighting has significant safety benefits. The {NZTA} Economic Evaluation Manual (EEM) quotes a 35% reduction in crashes as the effect of upgrading or improving lighting where lighting is poor. However, no well-established dose–response relationship to lighting parameters exists from which one can deduce benchmark levels of lighting for safety. This study looked at a sample of street lighting installations spread over the urban areas of nine territorial local authorities. Standard street lighting parameters were measured in the field using a variety of instruments including illuminance meter, luminance meter and digital camera. Field measurements were related to the ratio of night-time to day time crashes as a measure of night time safety vis-a-vis daytime safety. A statistically significant dose–response relationship was found between average road luminance and safety across all traffic volume groups, with an indication that the relationship may be stronger where more serious crashes are involved. Threshold increment was also a significant variable but not so longitudinal uniformity or overall uniformity. The results related to luminance will allow practitioners to better estimate the safety benefits of different levels of lighting resulting in better targeting of expenditure.

Keywords: Road

The objective of this paper is to develop crash estimation models at traffic analysis zone (TAZ) level as a function of land use characteristics. Crash data and land use data for the City of Charlotte, Mecklenburg County, North Carolina were used to illustrate the development of {TAZ} level crash estimation models. Negative binomial count models (with log-link) were developed as data was observed to be over-dispersed. Demographic/socio-economic characteristics such as population, the number of household units and employment, traffic indicators such as trip productions and attractions, and, on-network characteristics such as center-lane miles by speed limit were observed to be correlated to land use characteristics, and, hence were not considered in the development of {TAZ} level crash estimation models. Urban residential commercial, rural district and mixed use district land use variables were observed to be correlated to other land use variables and were also not considered in the development of the models. Results obtained indicate that land use characteristics such as mixed use development, urban residential, single-family residential, multi-family residential, business and, office district are strongly associated and play a statistically significant role in estimating {TAZ} level crashes. The coefficient for single-family residential area was observed to be negative, indicating a decrease in the number of crashes with an increase in single-family residential area. Models were also developed to estimate these crashes by severity (injury and property damage only crashes). The outcomes can be used in safety conscious planning, land use decisions, long range transportation plans, and, to proactively apply safety treatments in high risk TAZs.

Keywords: Crash

Abstract Although many researchers have estimated crash modification factors (CMFs) for specific treatments (or countermeasures), there is a lack of studies that explored the heterogeneous effects of roadway characteristics on crash frequency among treated sites. Generally, the {CMF} estimated by before–after studies represents overall safety effects of the treatment in a fixed value. However, as each treated site has different roadway characteristics, there is a need to assess the variation of {CMFs} among the treated sites with different roadway characteristics through crash modification functions (CMFunctions). The main objective of this research is to determine relationships between the safety effects of adding a bike lane and the roadway characteristics through (1) evaluation of {CMFs} for adding a bike lane using observational before–after with empirical Bayes (EB) and cross-sectional methods, and (2) development of simple and full {CMFunctions} which are describe the {CMF} in a function of roadway characteristics of the sites. Data was collected for urban arterials in Florida, and the Florida-specific full {SPFs} were developed. Moreover, socio-economic parameters were collected and included in {CMFunctions} and {SPFs} (1) to capture the effects of the variables that represent volume of bicyclists and (2) to identify general relationship between the {CMFs} and these characteristics. In order to achieve better performance of CMFunctions, data mining techniques were used. The results of both before–after and cross-sectional methods show that adding a bike lane on urban arterials has positive safety effects (i.e., {CMF} < 1) for all crashes and bike crashes. It was found that adding a bike lane is more effective in reducing bike crashes than all crashes. It was also found that the {CMFs} vary across the sites with different roadway characteristics. In particular, annual average daily traffic (AADT), number of lanes, {AADT} per lane, median width, bike lane width, and lane width are significant characteristics that affect the variation in safety effects of adding a bike lane. Some socio-economic characteristics such as bike commuter rate and population density also have significant effect on the variation in CMFs. The findings suggest that full {CMFunctions} showed better model fit than simple {CMFuncttions} since they account for the heterogeneous effects of multiple roadway and socio-economic characteristics. The proposed {CMFunctions} provide insights into bike lane design and selection of sites for bike lane installation for reducing crashes.

Keywords: Safety effectiveness

There are approximately 600,000 highway bridges in the United States. These structures differ from surface streets and highways in terms of their physical properties and operational characteristics, which in turn, affect the risk of motor-vehicle crashes and the kinds of crashes that occur. The purpose of this study was to identify motor-vehicle crash patterns and contributing factors to bridge crashes and related countermeasure opportunities on four urban bridges in the New York metropolitan area. A crash typology was developed using the narratives and diagrams in police crash reports in addition to standard police classifications of crashes. The final dataset contained records of 1,381 police-reported crashes. The four bridges studied had higher crash rates than their respective approach roads. Four major crash types accounted for approximately 90% of the bridge crashes. Primary collision factors are reviewed, and potential countermeasures are discussed.

Keywords: Bridges

Background The Fatality Analysis Reporting System (FARS) has data from all areas of the United States, but is limited to fatal crashes. The National Automotive Sampling System–General Estimates System (NASS–GES) includes all types of serious traffic crashes, but is limited to a few sampling areas. Combining the strengths of these two samples might offset their limitations. Methods Logistic regression (allowing for sample design, and conditional upon selected person-, event-, and geographic-level factors) was used to determine the propensity (PFC) for each injured person in 2002–2008 NASS–GES data to be in a fatal crash sample. NASS–GES subjects injured in fatal crashes were then reweighted by a factor of {WFC} = (1/PFC) to create a “pseudopopulation”. The weights (WFC) derived from NASS–GES were also applied to injured subjects in 2007 {FARS} data to create another pseudopopulation. Characteristics and mortality predictions from these artificial pseudopopulations were compared to those obtained using the original NASS–GES sample. The sum of {WFC} for {FARS} cases was also used to estimate the number of crash injuries for rural and urban locations, and compared to independently reported data. Results Compared to regression results using the original NASS–GES sample, unadjusted models based on fatal crash samples gave inaccurate estimates of covariate effects on mortality for injured subjects. After reweighting using WFC, estimates based upon the pseudopopulations were similar to results obtained using the original NASS–GES sample. The sum of {WFC} for {FARS} cases gave reasonable estimates for the number of crash injuries in rural and urban locations, and provided an estimate of the rural effect on mortality after controlling for other factors. Conclusions Weights derived from analysis of NASS–GES data (the inverse propensity for selection into a fatal crash sample) allow appropriate adjustment for selection bias in fatal crash samples, including FARS.

Keywords: Traffic crash

Crash modification factors (CMFs) are used to measure the safety impacts of changes in specific geometric characteristics. Their development has gained much interest following the adoption of {CMFs} by the recently released Highway Safety Manual (HSM) and SafetyAnalyst tool in the United States. This paper describes a study to develop {CMFs} for interchange influence areas on urban freeways in the state of Florida. Despite the very different traffic and geometric conditions that exist in interchange influence areas, most previous studies have not separated them from the rest of the freeway system in their analyses. In this study, a promising data mining method known as multivariate adaptive regression splines (MARS) was applied to develop {CMFs} for median width and inside and outside shoulder widths for “total” and “fatal and injury” (FI) crashes. In addition, {CMFs} were also developed for the two most frequent crash types, i.e., rear-end and sideswipe. {MARS} is characterized by its ability to accommodate the nonlinearity in crash predictors and to allow the impact of more than one geometric variable to be simultaneously considered. The methodology further implements crash predictions from the model to identify changes in geometric design features. Four years of crashes from 2007 to 2010 were used in the analysis and the results showed that MARS's prediction capability and goodness-of-fit statistics outperformed those of the negative binomial model. The influential variables identified included the outside and inside shoulder widths, median width, lane width, traffic volume, and shoulder type. It was deduced that a 2-ft increase in the outside and inside shoulders (from 10 ft to 12 ft) reduces {FI} crashes by 10% and 33%, respectively. Further, a 42-ft reduction in the median width (from 64 ft to 22 ft) increases the rear-end, total, and {FI} crashes by 473%, 263%, and 223%, respectively.

Keywords: Crash modification factors

Abstract The present study developed a Persian version of the Adolescent Road User Behaviour Questionnaire (ARBQ) and investigated the psychometric properties of the scale in a sample of school students in the province of Tehran (Iran). In total 1111 adolescents completed the Persian version of the ARBQ. Exploratory factor analysis, using the shortened 21-item version of the scale revealed the presence of three reliable factors which were also supported using confirmatory factor analysis. According to this research, engagement in dangerous playing in the road was significantly higher among males, residents of large urban areas, students from private schools, students in the south of Tehran, those who reported relatives or friends had been killed in a road crash and those with a personal history of road accidents. Moreover, older adolescents, those who reported relatives or friends having been killed in a road crash and those with a traffic accident history reported higher involvement in unsafe crossing behaviour. Females, older adolescents, residents of small urban areas, students from schools in small urban areas and those with an accident history also reported less frequent engagement in planned protective behaviours. This study confirms that the {ARBQ} is a useful framework for investigating adolescents’ on-road behaviours in Iran. This research also showed that adolescents put themselves at risk by engaging in hazardous behaviours. As is the case in most countries, this study revealed the need for interventions, such as education and enforcement to improve the on-road safety culture amongst Iranian adolescents.

Keywords: Psychometric assessment

AbstractProblem Walking, the simplest form of transportation has many benefits for pedestrians and the society. Yet, pedestrians are a vulnerable group of people and safety concerns are a significant barrier in one's decision to walk. Multiple signal related pedestrian countermeasures have been proposed to promote pedestrian safety. Although the safety impacts of individual strategies have been investigated, their relative effectiveness is little known. Furthermore, those effective in reducing pedestrian crashes may be at odds with motorist safety. Purpose In this study, we evaluate the relative effectiveness of four signal related pedestrian countermeasures in New York City – increasing the total cycle length, Barnes Dance, split phase timing, and signal installation – and examine potential trade-offs in their reducing pedestrian crashes and multiple vehicle crashes. Methods We adopted a rigorous two-stage design that first identifies a comparison group, corresponding to each treatment group, and then estimates a negative binomial model with the generalized estimating equation (GEE) method to further control confounding factors and within-subject correlation. Built environment characteristics are also accounted for. Results Set in a large urban area, this study shows trade-offs between improving pedestrian safety and motorist safety. The study finds that two of them – split phase timing and signal installation – are effective in reducing multiple vehicle crashes. Increasing total cycle length is most effective in promoting pedestrian safety, but its effect on motorist safety is insignificant. Among the four examined, Barnes Dance is the second most effective countermeasure in reducing pedestrian crashes and yet, it tends to increase multiple vehicle crashes, though the effect is insignificant. Takeaway for practice The findings indicate that selection and implementation of countermeasures for urban intersections should consider the types of conflicts and balance the time for different groups of road users at the intersections so that the countermeasure is targeted to the problem and the improvement of the safety of one group does not compromise the safety of other groups. It is suggested that increasing cycle length be implemented at intersections with wide streets and areas where there is a higher percentage of elderly pedestrians; Barnes Dance is best installed at areas with many pedestrians and a modest amount of traffic; split phase timing is most desirable for locations with turning movements and relatively narrow streets; and installation of new signals depends largely on the volume of pedestrian and vehicle traffic at the intersections as warranted by MUTCD.

Keywords: Traffic safety

Abstract We conducted a study of approximately 16,000 drivers under the age of 30 that had purchased a pay-as-you-drive insurance policy, where their risk of being involved in a crash was analyzed from vehicle tracking data using a global positioning system. The comparison of novice vs. experienced young drivers shows that vehicle usage differs significantly between these groups and that the time to the first crash is shorter for those drivers with less experience. Driving at night and a higher proportion of speed limit violations reduces the time to the first crash for both novice and experienced young drivers, while urban driving reduces the distance traveled to the first crash for both groups. Gender differences are also observed in relation to the influence of driving patterns on the risk of accident. Nighttime driving reduces the time to the first accident in the case of women, but not for men. The risk of an accident increases with excessive speed, but the effect of speed is significantly higher for men than it is for women among the more experienced drivers.

Keywords: Accident research

{ABSTRACTIntroduction} Motorcycle passengers comprise a considerable proportion of traffic crash victims. During a 5 year period (2006–2010) in Iran, an average of 3.4 pillion passengers are killed daily due to motorcycle crashes. This study investigated the main factors influencing crash severity of this group of road users. Method The Classification and Regression Trees (CART) method was employed to analyze the injury severity of pillion passengers in Iran over a 4 year period (2009–2012). Results The predictive accuracy of the model built with a total of 16 variables was 74%, which showed a considerable improvement compared to previous studies. The results indicate that area type, land use, and injured part of the body (head, neck, etc.) are the most influential factors affecting the fatality of motorcycle passengers. Results also show that helmet usage could reduce the fatality risk among motorcycle passengers by 28%. Practical Applications The findings of this study might help develop more targeted countermeasures to reduce the death rate of motorcycle pillion passengers.

Keywords: Motorcycle pillion passengers

Aim The study aims to clarify the most typical circumstances in which car crashes involving young drivers and leading to the occurrence of injuries and to consider the various licensing statuses of the drivers in such crashes. Method Young Swedish drivers born between 1984 and 1986 were followed up in the Police register (2003–2004) for their involvement in car crashes as drivers (n = 2448). A set of five variables (25 categories) descriptive of those crashes was analyzed simultaneously by means of cluster analysis. Associations between crash clusters and licensing status (including none), licensing duration and alcohol involvement were also measured. Results Five clusters were identified, typical of one or some specific crash type(s): single-vehicle in sparsely populated areas, front-on collisions, crashes at dawn or at dusk, turning, cars of later model, crashes in urban areas and speed limits below 50 km/h. Clusters differ in consequences and in the proportions of alcohol impaired drivers involved but not regarding proportions of novice drivers. Unlicensed drivers were found in excess in some clusters (especially single and night time crashes). Conclusion Young drivers are involved in crashes leading to injuries in rather specific circumstances. For some of them, novice drivers or even unlicensed drivers are over-represented, which points to the need for targeted counter-measures, alongside those general ones already in place.

Keywords: Young drivers

Introduction This paper utilizes generalized additive model to explore the potential non-linear relationship between crash frequency and exposure on different types of urban roadway segments. Methods Generalized additive models are used to analyze crash frequency data and compared with the commonly used crash rate method and generalized linear models using a five-year crash data set from Houston, Texas. Results The study shows that the relationship between crash frequency and exposure varies by segment type and the linearity may only approximately exist in certain segment types. In addition, the generalized additive modeling results suggest that such relationship curves may not be monotonic. Finally, this study demonstrates that generalized additive models in general provide better flexibility and modeling performance than generalized linear models. Impact on Industry The generalized additive model provides a very promising alternative for crash frequency modeling and other safety studies.

Keywords: Crash analysis

Abstract Traffic incidents are a major source of congestion and travel time uncertainty. Traditionally, extensive attention has been given to accidents in the view of safety when studying occurrence frequency. The regularity of incident frequency, however, deserves equal attention by practitioners and researchers, especially on urban expressways with dense ramps and high traffic volume. The objective of this study was to have a thorough exploration of environmental and traffic-related causative factors of incident rate on three urban expressways in central Shanghai City, including disability incidents and crash incidents. Incident data obtained by CCTV-monitoring system were used, which contain large quantities of minor and short-duration incidents. The disaggregation of expressway sections and time intervals of this study was rare in its scope: disability frequency is analyzed on an hourly basis and segment-hour aggregation is applied for crash frequency. To account for temporal correlation among different time intervals, Generalized Estimation Equation procedure was used in this paper. In particular, the effects of traffic interaction features on incident occurrence were analyzed by considering segment length, merging and diverging volume. Results showed that temporal correlation of crash incident occurrence was larger than that of disability occurrence. There is a significant relationship of disability rate with rain and temperature, and there was more risk of vehicle disability in dense-traffic and low-speed condition. It also pointed out that the regularity of crash incident occurrence is quite different from that of accidents on highways or rural freeways: Environmental factors exert little impact on crash occurrence except from visibility; Short segment, high merging and diverging volume increased crash rate remarkably.

Keywords: incident rate

Abstract Uncovering the temporal trend in crash counts provides a good understanding of the context for pedestrian safety. With a rareness of pedestrian crashes it is impossible to investigate monthly temporal effects with an individual segment/intersection level data, thus the time dependence should be derived from the aggregated level data. Most previous studies have used annual data to investigate the differences in pedestrian crashes between different regions or countries in a given year, and/or to look at time trends of fatal pedestrian injuries annually. Use of annual data unfortunately does not provide sufficient information on patterns in time trends or seasonal effects. This paper describes statistical methods uncovering patterns in monthly pedestrian crashes aggregated on urban roads in Connecticut from January 1995 to December 2009. We investigate the temporal behavior of injury severity levels, including fatal (K), severe injury (A), evident minor injury (B), and non-evident possible injury and property damage only (C and O), as proportions of all pedestrian crashes in each month, taking into consideration effects of time trend, seasonal variations and {VMT} (vehicle miles traveled). This type of dependent multivariate data is characterized by positive components which sum to one, and occurs in several applications in science and engineering. We describe a dynamic framework with vector autoregressions (VAR) for modeling and predicting compositional time series. Combining these predictions with predictions from a univariate statistical model for total crash counts will then enable us to predict pedestrian crash counts with the different injury severity levels. We compare these predictions with those obtained from fitting separate univariate models to time series of crash counts at each injury severity level. We also show that the dynamic models perform better than the corresponding static models. We implement the Integrated Nested Laplace Approximation (INLA) approach to enable fast Bayesian posterior computation. Taking {CO} injury severity level as a baseline for the compositional analysis, we conclude that there was a noticeable shift in the proportion of pedestrian crashes from injury severity A to B, while the increase for injury severity K was extremely small over time. This shift to the less severe injury level (from A to B) suggests that the overall safety on urban roads in Connecticut is improving. In January and February, there was some increase in the proportions for levels A and B over the baseline, indicating a seasonal effect. We found evidence that an increase in {VMT} would result in a decrease of proportions over the baseline for all injury severity levels. Our dynamic model uncovered a decreasing trend in all pedestrian crash counts before April 2005, followed by a noticeable increase and a flattening out until the end of the fitting period. This appears to be largely due to the behavior of injury severity level A pedestrian crashes.

Keywords: Compositional time series

Current literature does not adequately discuss India's quickly changing transportation scenario, especially road traffic crash (RTC) concerns. The objectives of this work were to (a) present the national {RTC} framework and a case study of Andhra Pradesh (AP); (b) analyze and identify risk types; (c) discuss trends and data deficiencies; and (d) recommend prevention strategies. During the period 1970–2009, the nation's road length increased at a compounded annual growth rate (CAGR) of 3.2%, whereas the number of registered vehicles, RTCs, and fatalities grew at 12%, 3.8%, and 5.7% {CAGR} respectively. Exposure risk dropped from 103 to 11 fatalities per 10 000 vehicles but increased from 2.7 to 10.8 fatalities per 100 000 people. In 2001, {AP} had 7.5% of the nation's population but 10.4% fatalities. In 2009, the share of urban:rural {RTCs} was 40%:60%, while 4%, 7%, 4.3%, and 7.1% of fatal crashes occurred near schools, bus stops, gas stations, and pedestrian crossings respectively. In 2009, 22% of fatal crashes were due to heavy vehicles, while motorized two-wheeler fatalities more than tripled during the 2001–2009 period. Vehicles under four years old were involved in 43% of the fatal crashes while 11% to 14% of the fatal crashes were due to ‘overturning’ and ‘head-on’ collisions; more than 75% of crashes were due to driver error. 42% of {RTCs} occurred at ‘uncontrolled’ intersections, while the crash risk at police-regulated locations was 40% less than at traffic signals. Recommended prevention strategies include: developing a road accident recording system and an access management policy; integrating safety into corridor design and road construction; undertaking capacity-building efforts; and expanding emergency response services.

Keywords: India

According to official statistics, a large percentage of crashes in Portugal are reported on urban roads. For instance, from 2004 to 2007, about 70% of all injury accidents and 43% of the fatalities occurred inside urban agglomerations. This important safety problem has also been observed on the urban network of Lisbon. Understanding this significant problem, the Government of the Portuguese Republic via its research grant agency – The Foundation for Science and Technology – funded a project whose primary objective consists of developing tools that would help estimating the safety performance of various components of the urban highway system in Lisbon. This paper documents one component of the safety tools that were developed and describes the steps that were taken to develop predictive models for estimating the safety performance of signalized and unsignalized intersections of Lisbon. Several crash predictive models were developed using the Poisson-gamma modeling framework. Two types of models were estimated: flow-only and models with covariates. They were estimated using crash and other related data collected at 44 three-legged and 50 four-legged intersections for the years 2004–2007, inclusively. It was found that some highway geometric design characteristics were associated with the crashes occurring at urban three- and four-legged intersections in Lisbon.

Keywords: Crash prediction models

Abstract Urban intersections are key locations of traffic crashes that contribute significantly to the economic losses. Safety management process undertaken by most states in the United States (U.S), is often referred to as the hazard elimination program which consists of three steps: (1) selections of hazardous locations, (candidate locations) where safety improvements are warranted, (2) development of countermeasures for potential reduction of crashes, (3) allocation of resources among the independent candidate locations in conformance to budgetary and other constraints. Often these three steps are independently considered with very limited detail on each step in the state planning agencies. This paper presents a simultaneous model which predicts the occurrence of crashes and allocates resources by maximizing benefits subjected to budget and other constraints. The analysis is carried out for a planning period of five years. The crash prediction is analysed as a negative binomial model. The resource allocation model is solved using branch and bound algorithm. Prediction and allocation is conducted simultaneously to achieve realistic results rather than analysing both steps independently. The allocation model further prioritizes the projects to be implemented to optimally distribute funds to maximize benefits. Model results reveal that the proposed approach can be used as a tool for resource allocation on highway safety projects for urban intersections.

Keywords: Negative Binomial model

Nilsson (1981) proposed power relationships connecting changes in traffic speeds with changes in road crashes at various levels of injury severity. Increases in fatal crashes are related to the 4th power of the increase in mean speed, increases in serious casualty crashes (those involving death or serious injury) according to the 3rd power, and increases in casualty crashes (those involving death or any injury) according to the 2nd power. Increases in numbers of crash victims at cumulative levels of injury severity are related to the crash increases plus higher powers predicting the number of victims per crash. These relationships are frequently applied in {OECD} countries to estimate road trauma reductions resulting from expected speed reductions. The relationships were empirically derived based on speed changes resulting from a large number of rural speed limit changes in Sweden during 1967-1972. Nilsson (2004) noted that there had been very few urban speed limit changes studied to test his power model. This paper aims to test the assumption that the model is equally applicable in all road environments. It was found that the road environment is an important moderator of Nilsson's power model. While Nilsson's model appears satisfactory for rural highways and freeways, the model does not appear to be directly applicable to traffic speed changes on urban arterial roads. The evidence of monotonically increasing powers applicable to changes in road trauma at increasing injury severity levels with changes in mean speed is weak. The estimated power applicable to serious casualties on urban arterial roads was significantly less than that on rural highways, which was also significantly less than that on freeways. Alternative models linking the parameters of speed distributions with road trauma are reviewed and some conclusions reached for their use on urban roads instead of Nilsson's model. Further research is needed on the relationships between serious road trauma and urban speeds.

Keywords: Speed

Context Existing studies have identified that, although to a lesser extent than individual factors such as males and young people, rural (compared to urban) communities represent a disproportionately high-risk of alcohol-related traffic crashes (ARTCs). To date, however, few studies have attempted to apply different costs to alcohol crashes of different severity, to provide more precise, and practically useful, data on which to base public health policy and intervention decisions. Objective The aim of this study is to quantify the per capita prevalence and differential costs of alcohol crashes of different levels of severity to determine the extent to which urban and rural geographical areas may differ in the costs attributable to ARTCs. Design A cross-sectional analysis of alcohol-related traffic crash and costs data from 2001 to 2007. Setting and participants Data from New South Wales, Australia. Main outcome measures Modified routinely collected traffic accident data to which costs relevant to alcohol crashes of different severity are applied. Results Although the rate per 10,000 population of alcohol-related crashes is 1.5 times higher in rural, relative to urban, communities, the attributable cost is four times higher, which largely reflects that rural alcohol-fatalities are seven to eight times more prevalent and costly. Conclusions Given that per capita alcohol-related fatal crashes in rural areas account for a disproportionately large proportion of the harms and costs associated with alcohol-related traffic crashes, the cost-effectiveness of public health interventions and public policy initiatives should consider the relative extent of ARTC-harm in rural versus urban communities.

Keywords: Alcohol

Abstract Many children do not travel safely in vehicles, with rural children often traveling less safely than urban children. Motor vehicle crashes were the leading cause of death of children aged from 1 to 14 years in the United States in 2011. Lack of education or inadequate parental education during well-child visits regarding proper child restraint within vehicles by health care providers (HCPs) in rural areas could be resulting in increased misuse of child restraints and lack of restraint use in rural areas. This study sought to determine rural–urban differences in frequency and accuracy of anticipatory guidance related to child passenger safety (CPS) provided by HCPs, in addition to rural–urban differences in {HCP} confidence in providing this counseling. {HCPs} from rural and urban areas in several upper Midwest states were surveyed about frequency and confidence of advice provided to parents related to {CPS} and their knowledge level on this subject. Urban {HCPs} were significantly more likely than rural {HCPs} to consistently provide advice to parents related to {CPS} across all age groups for children aged 12 years or younger. Differences were found between rural and urban {HCPs} regarding confidence in their ability to address parents׳ questions/concerns, and knowledge related to specific {CPS} issues. Significant differences exist in the frequency of {CPS} anticipatory guidance provision and confidence in accurate provision of {CPS} anticipatory guidance by rural and urban {HCPs} to parents. Significant differences also exist between rural and urban {HCPs} in relation to {CPS} knowledge. Differences may be due to increased levels of training for urban HCPs. This research is important as it adds to the compendium of knowledge related to {CPS} counseling patterns focused on reducing motor vehicle-related injuries and fatalities in children.

Keywords: Occupant safety

AbstractIntroduction This study identifies geometric, traffic, environmental, vehicle-related, and driver-related predictors of crash injury severity on urban freeways. Method The study takes advantage of the mixed logit model’s ability to account for unobserved effects that are difficult to quantify and may affect the model estimation, such as the driver’s reaction at the time of crash. Crashes of 5 years occurring on 89 urban freeway segments throughout the state of Florida in the United States were used. Examples of severity predictors explored include traffic volume, distance of the crash to the nearest ramp, and detailed driver’s age, vehicle types, and sides of impact. To show how the parameter estimates could vary, a binary logit model was compared with the mixed logit model. Results It was found that the at-fault driver’s age, traffic volume, distance of the crash to the nearest ramp, vehicle type, side of impact, and percentage of trucks significantly influence severity on urban freeways. Additionally, young at-fault drivers were associated with a significant severity risk increase relative to other age groups. It was also observed that some variables in the binary logit model yielded illogic estimates due to ignoring the random variation of the estimation. Since the at-fault driver’s age and side of impact were significant random parameters in the mixed logit model, an in-depth investigation was performed. It was noticed that back, left, and right impacts had the highest risk among middle-aged drivers, followed by young drivers, very young drivers, and finally, old and very old drivers. Impact on Industry To reduce side impacts due to lane changing, two primary strategies can be recommended. The first strategy is to conduct campaigns to convey the hazardous effect of changing lanes at higher speeds. The second is to devise in-vehicle side crash avoidance systems to alert drivers of a potential crash risk. Conclusions The study provided a promising approach to screening the predictors before fitting the mixed logit model using the random forest technique. Furthermore, potential countermeasures were proposed to reduce the severity of impacts.

Keywords: Mixed Logit

Abstract The research described in this paper explored the factors contributing to the injury severity resulting from pedestrian at-fault crashes in rural and urban locations in Alabama incorporating the effects of randomness across the observations. Given the occurrence of a crash, random parameter logit models of injury severity (with possible outcomes of major, minor, and possible or no injury) for rural and urban locations were estimated. The estimated models identified statistically significant factors influencing the pedestrian injury severities. The results clearly indicated that there are differences between the influences of a variety of variables on the injury severities resulting from urban versus rural pedestrian at-fault accidents. The results showed that some variables were significant only in one location (urban or rural) but not in the other location. Also, estimation findings showed that several parameters could be modeled as random parameters indicating their varying influences on the injury severity. Based on the results obtained, this paper discusses the effects of different variables on pedestrian injury severities and their possible explanations. From planning and policy perspective, the results of this study justify the need for location specific pedestrian safety research and location specific carefully tailored pedestrian safety campaigns.

Keywords: Pedestrian at-fault crashes

Objectives This study assessed the association between county level material deprivation and urbanization with fatal road traffic crashes involving young unlicensed drivers in the United States (US). Background Road traffic crashes have been positively associated with area deprivation and low population density but thus far few studies have been concerned specifically with young drivers, especially those that are unlicensed. Methods A county material deprivation index was derived from the Townsend Material Deprivation Index, with variables extracted from the {US} Census (2000). An urbanicity scale was adapted from the {US} Department of Agriculture's Rural–Urban Continuum Codes (2003). Data on fatal crashes involving a young unlicensed driver during a seven-year period (2000–2006; n = 3059) were extracted from the Fatality Analysis Reporting System. The effect of deprivation and urbanicity on the odds of the occurrence of at least one fatal crash at the county level was modeled by conditional and unconditional logistic regression. Results The conditional model found a positive association between material deprivation and a fatal crash involving a young unlicensed driver (OR = 1.19, 95% {CI} 1.17, 1.21). The interaction between urbanicity and material deprivation was negatively associated in suburban counties for fatal crashes (OR = 0.92, 95% {CI} 0.90, 0.95). Conclusions An association with material deprivation and the likelihood of a fatal crash involving a young unlicensed driver is a new finding. It can be used to inform specific county-level interventions and promote state licensing policies to provide equity in young people's mobility regardless of where they live.

Keywords: Unlicensed driving

A 20-month prospective study was conducted to investigate the effect of motorcycle crash experience on changes in risk taking among 2514 urban and 2304 rural students in Taiwan. Risk taking was assessed using a 14-item self-administered questionnaire at the beginning and end of the study. A risk-taking score for each student at the initial and the last follow-up assessments was generated from adding up points across all 14 items. For exposure variables, the study documented past motorcycle crash history at the initial assessment and collected detailed information about any motorcycle crash involvement that occurred during the study period. A general linear mixed model was applied to assess the effects of prior and recent crash involvements on the path of risk-taking behavior. The results show that at the initial assessment, students with crash experience had higher risk-taking levels than those without crash experience. However, crash experience, irregardless of whether it was measured in terms of crash history prior to the study, crash frequency, time elapsed since the last crash, or crash severity, did not significantly change the risk-taking path among students, even though its effect differed between urban and rural areas.

Keywords: Crash

Background Minimizing emergency medical service (EMS) response time is a central objective of prehospital care, yet the potential influence of built environment features such as urban sprawl on {EMS} system performance is often not considered. Purpose This study measures the association between urban sprawl and {EMS} response time to test the hypothesis that features of sprawling development increase the probability of delayed ambulance arrival. Methods In 2008, {EMS} response times for 43,424 motor-vehicle crashes were obtained from the Fatal Analysis Reporting System, a national census of crashes involving ≥1 fatality. Sprawl at each crash location was measured using a continuous county-level index previously developed by Ewing et al. The association between sprawl and the probability of a delayed ambulance arrival (≥8 minutes) was then measured using generalized linear mixed modeling to account for correlation among crashes from the same county. Results Urban sprawl is significantly associated with increased {EMS} response time and a higher probability of delayed ambulance arrival (p=0.03). This probability increases quadratically as the severity of sprawl increases while controlling for nighttime crash occurrence, road conditions, and presence of construction. For example, in sprawling counties (e.g., Fayette County GA), the probability of a delayed ambulance arrival for daytime crashes in dry conditions without construction was 69% (95% CI=66%, 72%) compared with 31% (95% CI=28%, 35%) in counties with prominent smart-growth characteristics (e.g., Delaware County PA). Conclusions Urban sprawl is significantly associated with increased {EMS} response time and a higher probability of delayed ambulance arrival following motor-vehicle crashes in the U.S. The results of this study suggest that promotion of community design and development that follows smart-growth principles and regulates urban sprawl may improve {EMS} performance and reliability.

Most traffic crashes in Chinese cities occur at signalized intersections. Research on the intersection safety problem in China is still in its early stage. The recent development of an advanced traffic information system in Shanghai enables in-depth intersection safety analyses using road design, traffic operation, and crash data. In Shanghai, the road network density is relatively high and the distance between signalized intersections is small, averaging about 200 m. Adjacent signalized intersections located along the same corridor share similar traffic flows, and signals are usually coordinated. Therefore, when studying intersection safety in Shanghai, it is essential to account for intersection correlations within corridors. In this study, data for 195 signalized intersections along 22 corridors in the urban areas of Shanghai were collected. Mean speeds and speed variances of corridors were acquired from taxis equipped with Global Positioning Systems (GPS). Bayesian hierarchical models were applied to identify crash risk factors at both the intersection and the corridor levels. Results showed that intersections along corridors with lower mean speeds were associated with fewer crashes than those with higher speeds, and those intersections along two-way roads, under elevated roads, and in close proximity to each other, tended to have higher crash frequencies.

Keywords: Signalized intersection

Abstract Crashes at rail level crossings (RLXs) remain a persistent but ill-defined safety issue. In urban areas, {RLXs} are typically located in areas of high workload and visual clutter, such as busy shopping strips. Despite this, the impact of such environments on driver behaviour and compliance with {RLX} controls is not well understood. This study sought to examine where drivers direct their attention on approach to urban {RLXs} located in busy shopping strip areas, and whether this differs between novice and experienced drivers. Participants drove an instrumented vehicle around a pre-defined urban route containing several active (flashing light with boom barriers) RLXs. Drivers’ visual scanning behaviour and cognitive processes were examined on approach to RLXs. The results suggest that {RLXs} were not a key focus of drivers’ attention. Further, rather than actively scanning, participants were over-reliant on {RLX} warning signals and the behaviour of surrounding vehicles to alert them to the presence of both trains and RLXs. This study provides important insights into drivers’ visual and cognitive behaviour on approach to urban {RLXs} located in areas of high visual demand.

Keywords: Rail level crossings

Abstract This study proposes a Bayesian spatial joint model of crash prediction including both road segments and intersections located in an urban road network, through which the spatial correlations between heterogeneous types of entities could be considered. A road network in Hillsborough, Florida, with crash, road, and traffic characteristics data for a three-year period was selected in order to compare the proposed joint model with three site-level crash prediction models, that is, the Poisson, negative binomial (NB), and conditional autoregressive (CAR) models. According to the results, the {CAR} and Joint models outperform the Poisson and {NB} models in terms of model fitting and predictive performance, which indicates the reasonableness of considering cross-entity spatial correlations. Although the goodness-of-fit and predictive performance of the {CAR} and Joint models are equivalent in this case study, spatial correlations between segments and the connected intersections are found to be more significant than those solely between segments or between intersections, which supports the employment of the Joint model as an alternative in road-network-level safety modeling.

Keywords: Crash prediction

Abstract This paper presents a probabilistic approach to measure the crash risk associated to an urban segment. This approach leads to a hotspot definition and identification using a probabilistic model defining the dependent variable as an indicator of a discrete choice. A binary choice model is used considering a binary dependent variable that differentiates a hotspot from a safe site set by the number of crashes per year per kilometre. The explanatory variables to set similar segments are based on average annual daily traffic, segment length, density of minor intersections. A threshold value for the number of crashes per kilometre is set to distinguish hotspots from safe sites. Based on this classification, a binary model is applied that allows the construction of an ordered site list using the probability of a site being a hotspot. A demonstration of the proposed methodology is provided using urban segment data from Porto, Portugal, covering a five-year period. The results of the binary model show a good fit. To evaluate and compare the probabilistic method with three usual hotspot identification methods described in the Highway Safety Manual, measures are used to test the performance of each method. Depending on the tests, actual data or simulated input, which are usually considered to set the “true” hotspots, were used. In general, the tests results indicate that the binary model performs better than the other three models. Nevertheless, it should be noted that the probabilistic approach provides an outcome that is quite different from the other methods, thus making difficult to ensure a linear comparison with the other methods. Overall, the study shows an alternative to hotspot identification using a risk measure in which the gains are the simplicity, the reliability, and the efficiency of model outcome.

Keywords: Hotspot identification

Urban road safety management is usually characterized by the lack of sufficient, good quality crash data and low budgets to obtain it even though many traffic accidents occur there. For example, 54 percent of road crashes in Spain take place in urban areas, and 10 percent of urban fatal crashes occur on crosstown roads, which are rural roads that traverse small communities. Traffic calming measures (TCMs) are often implemented on these parts of rural roads that traverse small communities in order to reduce both the frequency and severity of crashes by lowering speeds, but evaluation of their effectiveness has been limited. The objective of this study was to develop a methodology using continuous speed profiles to evaluate the safety effectiveness of {TCMs} on crosstown roads as part of an integrated system in the absence of historical data. Given the strong relationship between speed and crash experience, safety performance can be related to speed. Consequently, speed can be used indirectly as a surrogate safety measure in the absence of crash and speed data. Two indexes were defined in this study as surrogate safety measures based on the continuous speed profile: Ra and Ea. Ra represents the absolute accumulated speed variations relative to the average speed and is inversely related to accumulated speed uniformity; and Ea represents the accumulated speed variations above the speed limit and is directly related to accumulated speeding. Naturalistic data were collected using {GPS} trackers for 12 scenarios with different {TCM} spacings. Then, the indexes were applied to individual observed speed profiles (individual analysis) as well as the operating speed profile (global analysis). The values obtained from individual and global analysis were statistically different. Spacing lower than 110 m, which was found optimal from previous research, did not allow drivers to modify their speeds as the accumulated speed uniformity was quite similar regardless of the average operating speed; and, accumulated speeding was also minimized. Consequently, the scenarios where the {TCMs} were implemented according to the technical criteria presented a better design quality. On the other hand, age and gender differences did not seem to affect the average speeds or the accumulated speed uniformity and accumulated speeding.

Keywords: Surrogate safety measure

Abstract Ordos Municipality is a prefecture-level city in China’s Inner Mongolia Autonomous Region. The city emerged in the 2000s as a coalmining boomtown exploiting endowments equal to one sixth of China’s total proven coal reserve. After converting from rural to urban status in 2001, the local government also used the resource boom to vastly expand the urban areas of the municipality and stimulate broader industrialization. Rapid urban expansion helped to inflate a severe property bubble and spurred the formation of volatile informal financial networks. Crashes in the local property market and informal finance in 2011 caused a sharp downturn in the local economy. Ordos’ city-building agenda, with its strong emphasis on land development and lacking a broad industrial base, produced unstable economic conditions. Due to its recent problems, Ordos is now widely cited as a cautionary example for other resource-based cities in China.

Keywords: Ordos

Safety conscious planning is a new proactive approach towards understanding crashes. It requires a planning-level decision-support tool to facilitate proactive approach to assessing safety effects of alternative urban planning scenarios. The objective of this research study is to develop a series of aggregate crash prediction models (ACPM) that are consistent with the trip generation step of the conventional four-step demand models. The concept of crash generation models (CGMs) is introduced utilizing trip generation data in a generalized linear regression with the assumption of a negative binomial error structure. The relationship of crash frequencies in traffic analysis zones (TAZ) and number of trips generated by purpose is investigated. This translates into immediate checking of the impact of future trip generations on crash frequencies in comprehensive transportation-planning studies (i.e. ability to forecast crashes at each time-step trips are being forecasted). A good relation was seen between crash frequency and number of trips produced/attracted by purpose per TAZ.

Keywords: Safety planning

Studies of the crash experience of tractors pulling multiple trailers have reached different conclusions concerning the relationship of truck configuration to crash risk. A previous case-control study found a significant increase in crash risk for double-trailer trucks in the state of Washington. The present case-control study was done of tractor-trailers crashing on Indiana interstates during November 1989–March 1991. Controls were obtained for 25 % of the crash sites and were all tractor-trailers passing the crash sites during a traffic observation session one to four weeks following a crash on the same day of the week for 30 minutes at the same time of day. Logistic regression identified day of week, time of day, urban/rural area, and specific highway as significant predictors of controls' truck configuration. This model was applied to the cases to estimate the expected number of double-trailer cases. For all crashes combined, no increased crash risk was observed for doubles (Standardized Crash Ratio (SCR) = 83). Doubles were significantly underinvolved in multiple-vehicle crashes (SCR = 74), crashes on dry roads (SCR = 61), and crashes on wet (other than snow, ice, or slush) roads (SCR = 54). Doubles were significantly overinvolved in crashes on roads with snow, ice, or slush (SCR = 153). Because truck configuration was highly associated with driver age and work operation attributes among trucks in crashes, the absence of control data on these potential confounders precluded definitive assessment of the intrinsic risk of multiple versus single-trailer vehicles.

Keywords: Trucks

Motor vehicle crashes involving civilian and emergency vehicles (EVs) have been a known problem that contributes to fatal and nonfatal injuries; however, characteristics associated with civilian drivers have not been examined adequately. This study used data from The National Highway Traffic Safety Administration's Fatality Analysis Reporting System and the National Automotive Sampling System General Estimates System to identify driver, roadway, environmental, and crash factors, and consequences for civilian drivers involved in fatal and nonfatal crashes with in-use and in-transport EVs. In general, drivers involved in emergency–civilian crashes (ECCs) were more often driving: straight through intersections (vs. same direction) of four-points or more (vs. not at intersection); where traffic signals were present (vs. no traffic control device); and at night (vs. midday). For nonfatal ECCs, drivers were more often driving: distracted (vs. not distracted); with vision obstructed by external objects (vs. no obstruction); on dark but lighted roads (vs. daylight); and in opposite directions (vs. same directions) of the EVs. Consequences included increased risk of injury (vs. no injury) and receiving traffic violations (vs. no violation). Fatal {ECCs} were associated with driving on urban roads (vs. rural), although these types of crashes were less likely to occur on dark roads (vs. daylight). The findings of this study suggest drivers may have difficulties in visually detecting {EVs} in different environments.

Keywords: Motor vehicle crash

Work zones in the United States have approximately 700 traffic-related fatalities, 24 000 injury crashes, and 52 000 non-injury crashes every year. Due to future highway reconstruction needs, work zones are likely to increase in number, duration, and length. This study focuses on analyzing the effect of work zone duration mainly due to its policy-sensitivity. To do so, we created a unique dataset of California freeway work zones that included crash data (crash frequency and injury severity), road inventory data (average daily traffic (ADT) and urban/rural character), and work zone related data (duration, length, and location). Then, we investigated crash rates and crash frequencies in the pre-work zone and during-work zone periods. For the freeway work zones investigated in this study, the total crash rate in the during-work zone period was 21.5% higher (0.79 crashes per million vehicle kilometer (MVKM)) than the pre-work zone period (0.65 crashes per MVKM). Compared with the pre-work zone period, the increase in non-injury and injury crash rates in the during-work zone period was 23.8% and 17.3%, respectively. Next, crash frequencies were investigated using negative binomial models, which showed that frequencies increased with increasing work zone duration, length, and average daily traffic. The important finding is that after controlling for various factors, longer work zone duration significantly increases both injury and non-injury crash frequencies. The implications of the study findings are discussed in the paper.

Keywords: Work zones

Abstract Statistical data shows that single-vehicle crashes account for half of all traffic crashes on expressways in China, and previous research has indicated that main contributing factors were related to whether and how the inside shoulder was paved. The inside shoulder provides space for drivers to make evasive maneuvers and accommodate driver errors. However, lower-cost construction solutions in China have resulted in the design of numerous urban expressway segments that lack inside shoulders. This paper has two objectives. The first is to reveal the safety impacts of inside shoulders on urban expressways by driving simulator experiment. The second objective is to propose optimal range and recommended value of inside shoulder width for designing inside shoulders of urban expressways. The empirical data, including subjects’ eye movement data, heart rate (HR) and the lateral position of vehicles, were collected in a driving simulator. The data were analyzed to evaluate the safety impacts of the inside shoulder. The results have revealed that the inside shoulder has an impact on drivers’ visual perception, behaviors, and psychology; in particular, it has a significant effect on vehicle operations. In addition, this paper recommends the desired and optimal inside shoulder widths for eight-lane, two-way divided expressways.

Keywords: Traffic engineering

Problem: Freeway entrance and exit ramp interchanges are the sites of far more crashes per mile driven than other segments of interstate highways, but the characteristics and circumstances of ramp crashes have been the subject of relatively little recent research. Method: This study examined a sample of 1,150 crashes that occurred on heavily traveled urban interstate ramps in Northern Virginia. Based on a review of diagrams and narrative descriptions from police crash reports, the most common crash types were identified and examined for different roadway locations and ramp designs and by whether at-fault drivers were entering or exiting the freeway. Results: About half of all crashes occurred when at-fault drivers were in the process of exiting interstates, 36% occurred when drivers were entering, and 16% occurred at the midpoints of access roads or on ramps connecting two interstate freeways. Three major crash types—run-off-road, rear-end, and sideswipe/cutoff—accounted for 95% of crashes in the study. The crash type most frequently associated with exiting was run-off-road, and the types most common with entering drivers were rear-end or sideswipe/cutoff. Crashes most common on ramps—run-off-road crashes—frequently occurred when vehicles were exiting interstates at night, in bad weather, or on curved portions of ramps. Speed was often a factor. Crashes occurring on ramp margins (where ramps or access roads enter or exit) were most commonly of the sideswipe/cutoff type. These often involved at-fault passenger vehicles merging from entrance ramps into the sides of large trucks already on the freeway. The predominant crash type on access roads was rear-end crashes; congestion was a factor in these crashes. Alcohol was a reported factor in a sizeable proportion of run-off-road crashes occurring on ramps (14%) and ramp margins (30%). Impact on Industry: Candidate countermeasures for run-off-road crashes include geometric design changes to increase ramp design speed such as increasing curve radii. Speed-related crashes may be reduced by the use of speed cameras accompanied by publicity. Rear-end crash countermeasures could include surveillance systems that quickly detect unexpected congestion, incident response programs, and variable message signs to alert drivers to traffic congestion ahead. Countermeasures for sideswipe/cutoff crashes could include extending the length of acceleration lanes.

Keywords: Freeway entrance and exit ramps

For many older adults in most of the Western world, continued mobility (with associated health, well-being, independence and quality of life) means access to a private vehicle, either as a driver or as a passenger. However older driver serious injury and fatality rates per distance travelled are higher than middle-aged drivers, and crash and injury rates are likely to increase in the coming decades as a result of the ageing population, increased car ownership and overall travel amongst older people. Evidence suggests that contributory factors to this high risk are (for most) frailty, (for some) the high proportion of driving in urban areas, and (for a few) reduced fitness to drive as a result of medical conditions and associated functional limitations. Australasia has recently adopted the ‘Safe System’ approach which aims to manage vehicles, the road infrastructure, speeds, and the interactions between these components, to ensure that when crashes do occur, crash energies will remain at levels that minimize the probability of death and serious injury. A system which aspires to achieving Safe System objectives cannot ignore the challenges that older road users pose – and will pose – to the transport system. This paper discusses the so-called ‘older driver problem’, presents crash data and evidence of the impacts of driving location and reduced fitness to drive on crash risk, and recommends countermeasures within the ‘Safe System’ context, with particular reference to urban road design and operation.

Keywords: Safety

A cohort of 4729 junior college students in an urban and a rural area in Taiwan was followed up for a period of 20 months. Students’ characteristics, including riding exposures, as well as human, vehicular, and environmental factors were collected using one initial and three follow-up questionnaires. The Anderson–Gill (AG) multiplicative intensity model was used to determine the risk of a motorcycle crash over time while also allowing for the modeling of multiple events. The average response rate for the four assessments was 92%. The adjusted relative hazard (RH) for students living in the rural as opposed to the urban area for crashes was 1.67 at the beginning of the study but decreased to 0.66 by the end. Past motorcycle crash history, number of riding days, average riding distance, risk-taking level, alcohol consumption, and traffic violations were all significantly associated with an increased risk of being involved in a crash. Conversely, increasing age, riding experience, and automobile licensure were related to a decreased risk of crashing. Furthermore, helmet use was not independently related to the risk of crashing. In conclusion, a high-risk group predisposed to involvement in a motorcycle crash, including both non-injury and injury-related crashes, can be identified using selected risk factors for crash prevention among young riders.

Keywords: Adolescents

Abstract The number of pedestrian–motor vehicle accidents and pedestrian deaths in China surged in recent years. However, a large scale empirical research on pedestrian traffic crashes in China is lacking. In this study, we identify significant risk factors associated with fault and severity in pedestrian–motor vehicle accidents. Risk factors in several different dimensions, including pedestrian, driver, vehicle, road and environmental factors, are considered. We analyze 6967 pedestrian traffic accident reports for the period 2006–2010 in Guangdong Province, China. These data, obtained from the Guangdong Provincial Security Department, are extracted from the Traffic Management Sector-Specific Incident Case Data Report. Pedestrian traffic crashes have a unique inevitability and particular high risk, due to pedestrians’ fragility, slow movement and lack of lighting equipment. The empirical analysis of the present study has the following policy implications. First, traffic crashes in which pedestrians are at fault are more likely to cause serious injuries or death, suggesting that relevant agencies should pay attention to measures that prevent pedestrians from violating traffic rules. Second, both the attention to elderly pedestrians, male and experienced drivers, the penalty to drunk driving, speeding, driving without a driver's license and other violation behaviors should be strengthened. Third, vehicle safety inspections and safety training sessions for truck drivers should be reinforced. Fourth, improving the road conditions and road lighting at night are important measures in reducing the probability of accident casualties. Fifth, specific road safety campaigns in rural areas, and education programs especially for young children and teens should be developed and promoted. Moreover, we reveal a country-specific factor, hukou, which has significant effect on the severity in pedestrian accidents due to the discrepancy in the level of social insurance/security, suggesting that equal social security level among urban and rural people should be set up. In addition, establishing a comprehensive liability distribution system for non-urban areas and roadways will be conducive to both pedestrians’ and drivers’ voluntary compliance with traffic rules.

Keywords: Pedestrian–motor vehicle accident

In twenty of the countries composing the European Union (EU20), there are approximately 800,000 buses, equivalent to 0.35% of the total road vehicle fleet (230 million vehicles), while 10% of road trips are made by bus. Given these rates, bus crashes account for very few events, involving less than 1% of total road fatalities (ERF, 2010). It is evident that despite the significance of crashes involving buses and the assumption that public transport improves road safety by reducing vehicular traffic, few studies are available in the literature on crash data involving buses. The paper presents an overall analysis and comparison of crash data related to bus at European level. A more in depth study carried out at Italian National level provides a useful summary of practice in the area of bus safety management. The work focuses on the expertise of fleet managers to evaluate the effectiveness of different approaches and systems to reach higher safety standards. A survey form was defined referring to relevant factors affecting safety related to the driver (training, skills, performance evaluation and behavior), the vehicle (maintenance and advanced devices) and the road (traffic conflicts and urban road environment). Results provide useful information on the state of the art and current practices of urban public road transport in the area of road safety. Start inhibition, automatic door opening, and bus materials and internal architecture were unanimously considered the top safety items for bus passenger safety. Brake assistance and vehicle monitoring systems were also generally considered very effective.

Keywords: Bus

While it is generally agreed that traffic safety on urban arterials is closely associated with operational conditions, analysis of these relationships has been hampered by the absence of continuous measurements of operational variables such as traffic flow. Operational features of both peak and off peak were examined on a total 176 arterial segments from 23 different corridors within specific regions. These operational data, together with road segment characteristics, (e.g., segment length, number of lanes, median type), were used to construct models to estimate crash frequencies under various operational conditions for differing road segments. To account for the spatial correlations among the segments along the same corridors, Poisson-lognormal models with a two-level hierarchy under a Bayesian framework were used. Results showed significant relationships among operational conditions, roadway characteristics, and crash occurrence on these urban arterials. Lower average speeds at the corridor segment level were found to be associated with higher crash frequencies. The implications of using {FCD} data to assess operational conditions, and the use of hierarchical Bayesian models for predicting crash probabilities under different operational conditions are discussed.

Keywords: Urban arterial

This population-based study examined motor vehicle crash hospitalization rates and death rates among children and youth in rural and urban areas of the province of Alberta, Canada. Using police report data (1997–2002, inclusive), average annual motor vehicle crash hospitalization and death rates among those 0–19 years of age were calculated for rural and urban regions. Across all age and sex strata examined, both the hospitalization and the fatality rates were significantly higher in rural compared with urban regions. After adjusting for age, sex and calendar year, the relative risk of a motor vehicle crash hospitalization (rural versus urban) was 3.0 (95% CI: 2.8, 3.2). After adjusting for age, sex and calendar year, the relative risk of a motor vehicle crash fatality was 5.4 (95% CI: 4.2, 6.9). Motor vehicle crash injury hospitalization and fatality rates among children and youth in the province of Alberta are considerably higher in rural areas compared with urban areas. There is a need to identify social, demographic and environmental driving hazards associated with the rural environment.

Keywords: Child

Bends in roads can cause crashes but a recent study in the {UK} found that areas with mostly curved roads had lower crash rates than areas with straighter roads. This present study aimed to replicate the previous research in a different country. Variations in the number of fatal road crashes occurring between 1996 and 2005 in 73 territorial local authorities across New Zealand were modelled against possible predictors. The predictors were traffic flow, population counts and characteristics, car use, socio-economic deprivation, climate, altitude and road characteristics including four measures of average road curvature. The best predictors of the number of fatal crashes on urban roads, rural state highways and other rural roads were traffic flow, speed limitation and socio-economic deprivation. Holding significant factors constant, there was no evidence that {TLAs} with the most curved roads had more crashes than elsewhere. Fatal crashes on urban roads were significantly and negatively related to two measures of road curvature: the ratio of road length to straight distance and the cumulative angle turned per kilometre. Weaker negative associations on rural state highways could have occurred by chance. These results offer limited support to the suggestion that frequently occurring road bends might be protective.

Keywords: Crashes

Motor vehicle crashes involving rural drivers aged 75 years and over are more than twice as likely to result in a serious or fatal injury as those involving their urban counterparts. The current study examined some of the reasons for this using a database of police-reported crashes (2004–2008) to identify the environmental (lighting, road and weather conditions, road layout, road surface, speed limit), driver (driver error, crash type), and vehicle (vehicle age) factors that are associated with the crashes of older rural drivers. It also determined whether these same factors are associated with an increased likelihood of serious or fatal injury in younger drivers for whom frailty does not contribute to the resulting injury severity. A number of environmental (i.e., undivided, unsealed, curved and inclined roads, and areas with a speed limit of 100 km/h or greater) and driver (i.e., collision with a fixed object and rolling over) factors were more frequent in the crashes of older rural drivers and additionally associated with increased injury severity in younger drivers. Moreover, when these environmental factors were entered into a logistic regression model to predict whether older drivers who were involved in crashes did or did not sustain a serious or fatal injury, it was found that each factor independently increased the likelihood of a serious or fatal injury. Changes, such as the provision of divided and sealed roads, greater protection from fixed roadside objects, and reduced speed limits, appear to be indicated in order to improve the safety of the rural driving environment for drivers of all ages. Additionally, older rural drivers should be encouraged to reduce their exposure to these risky circumstances.

Keywords: Older drivers

This paper employs information from the advanced traffic management system (ATMS) of Kaohsiung, Taiwan to help differentiate those crash-prone intersections by discriminant analysis. From the 25,604 records of 2005, 1977 crashes that occurred at 119 intersections with traffic exposure data were compiled to calibrate and validate the model. The road attributes of crash records, traffic control devices and movement exposure are the three types of data used as predicting variables. The correct ratios for model calibration and validation range from 78.33% to 67.80%. if traffic movements are removed, the correct ratios become slightly lowered to 76.67% to 66.10%. Research findings reveal that with or without inclusion of exposure data in identifying high crash-prone intersections for an urban environment does not make a significant difference. in addition, layout and traffic control devices could possibly explain about 66.10 ∼ 78.33% of the possibility that an intersection will become a high crash intersection. it suggests that the developed approach could be a countermeasure for budget constraints and difficulties in continuation of exposure data collection, and the information of {ATMS} could help identify crash-prone urban intersections.

Keywords: ATMS

A study sponsored by the National Highway Traffic Safety Administration performed functional assessments on approximately 700 drivers age 70 and older who presented for license renewal in urban, suburban, and rural offices of the Maryland Motor Vehicle Administration. This volunteer sample received a small compensation for study participation, with an assurance that their license status would not be affected by the results. A comparison with all older drivers who visited the same sites on the same days indicated that the study sample was representative of Maryland older drivers with respect to age and prior driving safety indices. Relationships between drivers’ scores on a computer touchscreen version of the Maze Test and prospective crash and serious moving violation experience were analyzed. Results identified specific mazes as highly significant predictors of future safety risk for older drivers, with a particular focus on non-intersection crashes. Study findings indicate that performance on Maze Tests was predictive of prospective crashes and may be useful, as a complement to other, established cognitive screening tools, in identifying at-risk older drivers.

Keywords: Crash risk

Abstract Hotspot identification (HSID) is of great importance to land transport authorities (e.g. the Land Transport Authority (LTA) of Singapore) in their efforts to improve the safety of highways. According to a survey of experienced engineers at the {LTA} of Singapore, we draw the conclusion that the severity of crashes should not be neglected in the {HSID} process. Accordingly, in this technical note, societal risk-based simple ranking and empirical Bayesian methods are proposed to identify the hotspots in a Singapore expressway on the basis of the detailed three-year casualty data in the Historical Crash Damage (HCD) database. We further conduct a consistency analysis to compare the societal risk-based method and the conventional frequency-based method. The consistency analysis reports that (1) the frequency-based method is more consistent than the societal risk-based method, and (2) the empirical Bayesian method is more consistent than the simple ranking method.

Keywords: Societal risk

Background Fatality rates from rural vehicular trauma are almost double those found in urban settings. It has been suggested that increased prehospital time is a factor that adversely affects fatality rates in rural vehicular trauma. By linking and analyzing Alabama's statewide prehospital data, emergency medical services (EMS) prehospital time was assessed for rural and urban vehicular crashes. Methods An imputational methodology permitted linkage of data from police motor vehicle crash (MVC) and {EMS} records. {MVCs} were defined as rural or urban by crash location using the United States Census Bureau criteria. Areas within Alabama that fell outside the Census Bureau definition of urban were defined as rural. Prehospital data were analyzed to determine {EMS} response time, scene time, and transport time in rural and urban settings. Results Over a 2-year period from January 2001 through December 2002, data were collected from {EMS} Patient Care Reports and police crash reports for the entire state of Alabama. By using an imputational methodology and join specifications, 45,763 police crash reports were linked to {EMS} Patient Care Reports. Of these, 34,341 (75%) were injured in rural settings and 11,422 (25%) were injured in urban settings. A total of 714 mortalities were identified, of which 611 (1.78%) occurred in rural settings and 103 (.90%) occurred in urban settings (P < .0001). When mortalities occurred, the mean {EMS} response time in rural settings was 10.67 minutes and 6.50 minutes in urban settings (P < .0001). When mortalities occurred, the mean {EMS} scene time in rural settings was 18.87 minutes and 10.83 minutes in urban settings (patients who were dead on scene and extrication patients were excluded from both settings) (P < .0001). When mortalities occurred, the mean {EMS} transport time in rural settings was 12.45 minutes and 7.43 minutes in urban settings (P < .0001). When mortalities occurred, the overall mean prehospital time in rural settings was 42.0 minutes and 24.8 minutes in urban settings (P < .0001). The mean {EMS} response time for rural {MVCs} with survivors was 8.54 minutes versus a mean of 10.67 minutes with mortalities (P < .0001). The mean {EMS} scene time for rural {MVCs} with survivors was 14.81 minutes versus 18.87 minutes with mortalities (patients who were dead on scene and extrication patients were excluded) (P = .0014). Conclusions Based on this statewide analysis of MVCs, increased {EMS} prehospital time appears to be associated with higher mortality rates in rural settings.

Keywords: Rural

Abstract Safety performance functions (SPFs) are a required input to the newly released SafetyAnalyst software tool. Although SafetyAnalyst provides default {SPFs} that were developed based on data from multiple states in the United States, agencies have the option to calibrate local {SPFs} to better reflect their local conditions. However, the benefit from local calibration of {SPFs} is unclear and may vary from state to state. Using statistical goodness-of-fit measures and visual plots, this paper compares the performance of locally-calibrated {SPFs} using Florida data with the default {SPFs} from SafetyAnalyst for both freeway interchange influence areas and basic segments. An interchange influence area is one that extends 0.3 miles upstream and downstream of the respective gore point. Unlike for intersections, an automatic process for segmenting the influence areas for interchanges based on the above definition is relatively complex. Therefore, this paper also describes a spatial method to automatically segment a freeway facility into interchange influence areas and basic segments. Using four years of local crash data (2007–2010) from Florida, {SPFs} for both types of segments for both urban and rural areas were developed using the negative binomial regression model. The results showed that Florida-specific {SPFs} generally produced better-fitted models than the calibrated SafetyAnalyst default SPFs. This was clear in that the majority of Florida-specific models had higher Freeman–Tukey R-square ( R {FT} 2 ), as well as lower mean absolute deviance (MAD) and mean square prediction error (MSPE) estimates. Overall, the results suggest that agencies implementing SafetyAnalyst could improve their crash prediction by developing local-specific SPFs.

Keywords: Safety performance functions

On-street parking is associated with elevated crash risk. It is not known how drivers’ mental workload and behaviour in the presence of on-street parking contributes to, or fails to reduce, this increased crash risk. On-street parking tends to co-exist with visually complex streetscapes that may affect workload and crash risk in their own right. The present paper reports results from a driving simulator study examining the effects of on-street parking and road environment visual complexity on driver behaviour and surrogate measures of crash risk. Twenty-nine participants drove a simulated urban commercial and arterial route. Compared to sections with no parking bays or empty parking bays, in the presence of occupied parking bays drivers lowered their speed and shifted their lateral position towards roadway centre to compensate for the higher mental workload they reported experiencing. However, this compensation was not sufficient to reduce drivers’ reaction time on a safety-relevant peripheral detection task or to an unexpected pedestrian hazard. Compared to the urban road environments, the less visually complex arterial road environment was associated with speeds that were closer to the posted limit, lower speed variability and lower workload ratings. These results support theoretical positions that proffer workload as a mediating variable of speed choice. However, drivers in this study did not modify their speed sufficiently to maintain safe hazard response times in complex environments with on-street parking. This inadequate speed compensation is likely to affect real world crash risk.

Keywords: Driving simulation

Introduction The study aims at identifying traffic/highway design/driver-vehicle information significantly related with fatal/severe crashes on urban arterials for different crash types. Since the data used in this study are observational (i.e., collected outside the purview of a designed experiment), an information discovery approach is adopted for this study. Method Random Forests, which are ensembles of individual trees grown by {CART} (Classification and Regression Tree) algorithm, are applied in numerous applications for this purpose. Specifically, conditional inference forests have been implemented. In each tree of the conditional inference forest, splits are based on how good the association is. Chi-square test statistics are used to measure the association. Apart from identifying the variables that improve classification accuracy, the methodology also clearly identifies the variables that are neutral to accuracy, and also those that decrease it. Results The methodology is quite insightful in identifying the variables of interest in the database (e.g., alcohol/ drug use and higher posted speed limits contribute to severe crashes). Failure to use safety equipment by all passengers and presence of driver/passenger in the vulnerable age group (more than 55 years or less than 3 years) increased the severity of injuries given a crash had occurred. A new variable, ‘element’ has been used in this study, which assigns crashes to segments, intersections, or access points based on the information from site location, traffic control, and presence of signals. Impact The authors were able to identify roadway locations where severe crashes tend to occur. For example, segments and access points were found to be riskier for single vehicle crashes. Higher skid resistance and k-factor also contributed toward increased severity of injuries in crashes.

Keywords: Multilane arterials

Resurfacing is one of the more common construction activities on highways. While its effect on riding quality on any type of roadway is obviously positive; its impact on safety as measured in terms of crashes is far from obvious. This study examines the safety effects of the resurfacing projects on multilane arterials with partially limited access. Empirical Bayes method, which is one of the most accepted approaches for conducting before–after evaluations, has been used to assess the safety effects of the resurfacing projects. Safety effects are estimated not only in terms of all crashes but also rear-end as well as severe crashes (crashes involving incapacitating and fatal injuries). The safety performance functions (SPFs) used in this study are negative binomial crash frequency estimation models that use the information on ADT, length of the segments, speed limit and number of lanes. These {SPFs} are segregated by crash groups (all, rear-end, and severe), length of the segments being evaluated, and land use (urban, suburban, and rural). The results of the analysis show that the resulting changes in safety following resurfacing projects vary widely. Evaluating additional improvements carried out with resurfacing activities showed that all (other than sidewalk improvements for total crashes) of them consistently led to improvements in safety of multilane arterial sections. It leads to the inference that it may be a good idea to take up additional improvements if it is cost effective to do them along with resurfacing. It was also found that the addition of turning lanes (left and/or right) and paving shoulders were two improvements associated with a project's relative performance in terms of reduction in rear-end crashes.

Keywords: Resurfacing

Speeding is recognized as a major contributing factor in traffic crashes. In order to reduce speed-related crashes, the city of Scottsdale, Arizona implemented the first fixed-camera photo speed enforcement program (SEP) on a limited access freeway in the US. The 9-month demonstration program spanning from January 2006 to October 2006 was implemented on a 6.5 mile urban freeway segment of Arizona State Route 101 running through Scottsdale. This paper presents the results of a comprehensive analysis of the impact of the {SEP} on speeding behavior, crashes, and the economic impact of crashes. The impact on speeding behavior was estimated using generalized least square estimation, in which the observed speeds and the speeding frequencies during the program period were compared to those during other periods. The impact of the {SEP} on crashes was estimated using 3 evaluation methods: a before-and-after (BA) analysis using a comparison group, a {BA} analysis with traffic flow correction, and an empirical Bayes {BA} analysis with time-variant safety. The analysis results reveal that speeding detection frequencies (speeds ≥ 76 mph) increased by a factor of 10.5 after the {SEP} was (temporarily) terminated. Average speeds in the enforcement zone were reduced by about 9 mph when the {SEP} was implemented, after accounting for the influence of traffic flow. All crash types were reduced except rear-end crashes, although the estimated magnitude of impact varies across estimation methods (and their corresponding assumptions). When considering Arizona-specific crash related injury costs, the {SEP} is estimated to yield about 17 million in annual safety benefits.

Keywords: Safety

This article examines how a creative city project in Yokohama regenerated urban spaces before and during the 2008 financial crisis. Japanese cases can broaden our view of post-crash effects and policies. Japan avoided financial entanglements that plague the {US} and much of Europe. However, its export-oriented economy, which never recovered from a long period of stagnation, now suffers because of the declining purchasing power of its Western trading partners. Moreover, the direct role of the state in urban policy suggests a different context than that theorized in Western accounts of urban entrepreneurialism (or neo-liberalism): the latter stresses the role of municipal governments and developers in using creative city policies to create sanitized forms of urban redevelopment. To address the gap in knowledge about this sort of process in Japan, I use strategic informants, observations and secondary data to examine how creative city projects helped transform Yokohama’s Kogane-cho neighborhood from an enclave of brothels to an art district. In contrast to Western cases which feature local government and development interests, I show how creative city policies also were influenced by the interactions of neighborhood groups, provincial police and a national economic development policy encouraging quality of life measures, including crime control in entertainment districts. National stimulus funds have sustained the quality of life initiatives, but the art district’s homogeneity raises doubts about its status as a creative milieu.

Keywords: Creative city

The use of roundabouts improves intersection safety by eliminating or altering conflict types, reducing crash severity, and causing drivers to reduce speeds. However, roundabout performances can degrade if precautions are not taken during either the design or the operation phase. Therefore, additional information on the safety of the roundabouts is extremely helpful for planners and designers in identifying existing deficiencies and in refining the design criteria currently being used. The aim of the paper was to investigate the crash contributory factors in 15 urban roundabouts located in Italy and to study the interdependences between these factors. The crash data refer to the period 2003–2008. The identification of the crash contributory factors was based on site inspections and rigorous analyses performed by a team of specialists with a relevant road safety engineering background. Each roundabout was inspected once every year from 2004 to 2009, both in daytime and in nighttime. Overall, 62 different contributory factors and 2156 total contributory factors were identified. In 51 crashes, a single contributory factor was found, whereas in the other 223 crashes, a combination of contributory factors was identified. Given the large amount of data, the interdependences between the contributory factors and between the contributory factors and the different crash types were explored by an association discovery. Association discovery is the identification of sets of items (i.e., crash contributory factors and crash types in our study) that occur together in a given event (i.e., a crash in our study). The rules were filtered by support, confidence, and lift. As a result, 112 association rules were discovered. Overall, numerous contributory factors related to the road and environment deficiencies but not related to the road user or to the vehicle were identified. The most important factors related to geometric design were the radius of deflection and the deviation angle. In existing roundabouts, the improvement of these factors might be quite expensive, but the crucial role of a moderate radius of deflection and a large deviation angle in the design of new roundabouts was stressed. Many of the contributory factors were related to markings and signs, and these factors could be easily removed with low-cost safety measures. Furthermore, because of the association between the markings, signs, and geometric design contributory factors, the study results suggest that the improvement in markings and signs might also have a significant effect in the sites where geometric design deficiencies were identified as contributory factors.

Keywords: Roundabouts

Abstract This paper presents a safety-based path finding methodology for older drivers and bicyclists in an urban area. The paths are estimated based on costs consisting of both safety and travel time. Safety is evaluated against potential risk of a crash involving an older driver (or a bicyclist) with other vehicles present on the road. To accomplish this, simple formulations are developed for safety indicators of streets and intersections, which are actually generic irrespective of the type of road user. Traffic attributes such as speed and density, driver attributes such as perception-reaction time and street attributes of length and tire-to-road friction coefficient are taken into account in building the safety indicators. Thus, the safety indicators do not necessarily require historical crash data which may or may not be available during path finding. Subsequently, a multi-objective shortest path algorithm is presented that identifies the best path (the non-inferior path) from amongst a set of selected safest paths with due considerations to travel time incurred on each. A simple application example of the proposed methodology is demonstrated on an existing street network system from the City of College Station, Texas. The contributions of this research are twofold – first, the safety indicators can be used by planners in determining high crash potential sites – streets and/or intersections – and second, the safety-based path finding methodology developed in this paper can be integrated with modern day route planning devices and tools in guiding older drivers and bicyclists within an Intelligent Transportation Systems framework.

Keywords: Older drivers

Crashes between cars and trains at rail level crossings are problematic worldwide. Despite this, key facets of driver behaviour at rail level crossings, such as situation awareness and decision making, remain ambiguous. This is largely down to the inability of existing methodologies to describe or evaluate the cognitive aspects of driver behaviour when negotiating rail level crossings. This paper showcases an on-road approach for examining driver situation awareness at rail level crossings. The study presented involved participants, classified either as novice or experienced drivers, providing concurrent verbal protocols as they drove a pre-determined urban route incorporating four rail level crossings. Driver situation awareness was modelled using a network analysis-based approach and the structure and content of the networks was assessed. The analysis revealed key differences between novice and experienced drivers situation awareness at rail level crossings. In closing, the benefits of the on-road approach are discussed and a series of wider driver behaviour applications are proposed.

Keywords: Situation awareness

This paper proposes a reformulation of count models as a special case of generalized ordered-response models in which a single latent continuous variable is partitioned into mutually exclusive intervals. Using this equivalent latent variable-based generalized ordered response framework for count data models, we are then able to gainfully and efficiently introduce temporal and spatial dependencies through the latent continuous variables. Our formulation also allows handling excess zeros in correlated count data, a phenomenon that is commonly found in practice. A composite marginal likelihood inference approach is used to estimate model parameters. The modeling framework is applied to predict crash frequency at urban intersections in Arlington, Texas. The sample is drawn from the Texas Department of Transportation (TxDOT) crash incident files between 2003 and 2009, resulting in 1190 intersection-year observations. The results reveal the presence of intersection-specific time-invariant unobserved components influencing crash propensity and a spatial lag structure to characterize spatial dependence. Roadway configuration, approach roadway functional types, traffic control type, total daily entering traffic volumes and the split of volumes between approaches are all important variables in determining crash frequency at intersections.

Keywords: Count data

Abstract Traditionally traffic flow models have been based on analogous physical phenomena. Though these models have been successful in representing traffic flow, there is a need to provide a systematic behavioural explanation for their existence. One such model is the two-fluid model which is analogous to the principles of Bose–Einstein condensation of particles at low temperatures. The model has been extensively used to characterize the quality of traffic on urban networks and arterial streets. The two parameters of the model essentially represent ‘free flow’ travel time and level of interaction among vehicles. Though the studies have found the parameters of the two-fluid model to be significantly correlated with driver behaviour (aggressive/conservative) and crash rates, no systematic behavioural explanation has been found. This paper proposes a behavioural framework based on individual trade-off behaviour to explain the two-fluid model phenomenon. The two-fluid model is derived based on a driver’s attempt to maximize his quality of travel, by travelling fast while maintaining safety. Contrary to earlier assumptions the proposed framework shows the two parameters to be correlated. The theoretical framework was tested using two-fluid model data from various cities. The data was also used to estimate the effects of geometric factors on the perception of likelihood of a crash and the severity of the crash that affect the two-fluid model. Increase in the fraction of one-way streets was found to reduce the driver’s perception of likelihood to crash. While reduction in the fraction of one way streets and increase in average number of lanes per street, signal density and fraction of actuated signals increased the perceived level of severity of a crash.

Keywords: Two-fluid model

The two-fluid model for vehicular traffic flow explains the traffic on arterials as a mix of stopped and running vehicles. It describes the relationship between the vehicles’ running speed and the fraction of running vehicles. The two parameters of the model essentially represent ‘free flow’ travel time and level of interaction among vehicles, and may be used to evaluate urban roadway networks and urban corridors with partially limited access. These parameters are influenced by not only the roadway characteristics but also by behavioral aspects of driver population, e.g., aggressiveness. Two-fluid models are estimated for eight arterial corridors in Orlando, {FL} for this study. The parameters of the two-fluid model were used to evaluate corridor level operations and the correlations of these parameters’ with rates of crashes having different types/severity. Significant correlations were found between two-fluid parameters and rear-end and angle crash rates. Rate of severe crashes was also found to be significantly correlated with the model parameter signifying inter-vehicle interactions. While there is need for further analysis, the findings suggest that the two-fluid model parameters may have potential as surrogate measures for traffic safety on urban arterial streets.

Keywords: Two-fluid model

Many states are striving to keep their deer population to a sustainable and controllable level, while maximizing public safety. In Iowa, measures to control the deer population include annual deer hunts and special deer herd management plans in urban areas. While these plans may in effect reduce the deer population, traffic safety in these areas has not been fully assessed. Using deer population data from the Iowa Department of Natural Resources and data on deer-vehicle crashes and deer carcass removals from the Iowa Department of Transportation, we examine the relationship between deer-vehicle collisions, deer density, and land use in select urban deer management zones in Iowa. Further, we estimate models to investigate the factors that influence the frequency and severity of deer-vehicle crashes in these zones. The estimation results showed that multiple factors affect deer-vehicle crashes and corresponding injury outcomes in urban management zones. The identified roadway and non-roadway factors could be useful for identifying locations on the transportation system that significantly impact deer species and safety, and determining appropriate countermeasures for mitigation.

Keywords: Deer-vehicle crashes

Traffic safety researchers have long known that the majority of fatal crashes occur on rural roads, but it is not clear whether these crashes involve people who live in rural areas or residents of urban areas traveling on rural roads. `Geodemographic' market-research tools allow determination of the urbanization of drivers' residence locations from their postal `zip code.' Using data from the 1988–1992 files of the Fatal Accident Reporting System (FARS) maintained by the National Highway Traffic Safety Administration (NHTSA), this study determined the residence location of several subgroups of drivers involved in fatal crashes. Not only did the majority of fatal crashes occur in rural areas, but the majority of fatal crashes involved rural and small-town residents, and the majority of the rural and small-town residents involved in fatal crashes were traveling on rural roads.

Keywords: fatal crashes

An analysis of 2000–2007 single vehicle rollover fatalities in three Australian states was carried out using data from the Australian National Coroners Information System. In this paper, successive selection criteria were applied to the initial dataset to analyse:- Occupant fatalities in single passenger car crashes (1743 cases), - Occupant fatalities in single passenger car rollovers (474 cases), overall, rollovers accounted for 35% of all occupant fatalities in a single vehicle transport injury event. For these fatalities, the occupant was ejected or stayed contained in equal proportions. However, results showed strong disparities between the more urban and densely populated states of New South Wales and Victoria, compared to the Northern Territory in terms of crash type distribution and containment of the occupant. Differences were also found in rollover initiation, speed at initiation and number of turns. Overall, the strongest association of fatal neck/thoracic spine injuries with head injuries was found for the contained, restrained occupant. This analysis of single vehicle rollover fatalities is consistent with previous findings. It also shows that in Australia, strategies for rollover injury risk mitigation will need to take into account a broad range of characteristics to be effective.

Keywords: Rollover crashes

In many developing urban settings, economic growth and motorization are coupled with increasing rates of road traffic injuries (RTIs). By highlighting typical sites and circumstances at/in which car crashes occur, more specific targets for prevention can be identified. The study is based on police data for a 1-year period and covers the Chaoyang District, the biggest district of Beijing City. Focus is placed on crash patterns and their distribution by types of road and areas. Both fatal and non-fatal crashes are considered (n = 754). In the main, the crashes occurred in relatively favorable driving circumstances (e.g., sunny weather, flat and straight roads, asphalted roads, and good traffic signals and road markings). They were also quite evenly distributed over time of day, day of week and season. Five crash patterns were highlighted, of which three were strongly associated with specific areas and four with specific types of road. The study supports the idea that type of road and {RTI} severity or pattern are closely related. It contributes to the development of context-relevant prevention measures aimed at reducing road crashes and minimizing their consequences and also supports safe planning of the road traffic environment.

Keywords: Car crash

Abstract The research described in this paper analyzed injury severities at a disaggregate level for single-vehicle (SV) and multi-vehicle (MV) large truck at-fault accidents for rural and urban locations in Alabama. Given the occurrence of a crash, four separate random parameter logit models of injury severity (with possible outcomes of major, minor, and possible or no injury) were estimated. The models identified different sets of factors that can lead to effective policy decisions aimed at reducing large truck-at-fault accidents for respective locations. The results of the study clearly indicated that there are differences between the influences of a variety of variables on the injury severities resulting from urban vs. rural {SV} and {MV} large truck at-fault accidents. The results showed that some variables were significant only in one type of accident model (SV or MV) but not in the other accident model. Again, some variables were found to be significant in one location (rural or urban) but not in other locations. The study also identified important factors that significantly impact the injury severity resulting from {SV} and {MV} large truck at-fault accidents in urban and rural locations based on the estimated values of average direct pseudo-elasticity. A careful study of the results of this study will help policy makers and transportation agencies identify location specific recommendations to increase safety awareness related to large truck involved accidents and to improve overall highway safety.

Keywords: Large truck at-fault crashes

Efforts to reduce urban crash rates have been hampered by a lack of information about motor vehicle crash types. The present study is based on a systematic sample of 4,526 police crash reports from four urban areas. The sample was weighted to give each area equal representation. Diagrams and narrative descriptions from each report were reviewed, and the most common crash types based on precrash driver/ vehicle behavior, were identified. Fourteen crash types were defined, and five of these were found to account for 76% of all crash events and 83% of injury crashes. Although the rank order of the five types differed from city to city, they accounted for the vast majority (69%–81%) of the crashes in each. Potential countermeasures are discussed based on the predominant crash types identified in this study. For example, ran traffic control crashes, the most common type, might be reduced by changes in signal timing, providing all-red signal intervals, increasing sign visibility, and increasing sight distances.

Keywords: Urban crashes

AbstractIntroduction Traffic crash mortality is higher in rural areas, but it is unclear whether this is due to greater injury severity, time delays, or Emergency Medical Services (EMS) deficiencies. Methods Data from 2002–2003 were combined from the Fatality Analysis Reporting System (FARS) and an “expanded version” of the National Automotive Sampling System (NASS) Crashworthiness Data System (CDS). Weighted Cox and Weibull models for survival time (tSURV) were estimated, with time-varying covariates (TVC) having constant effects for specified time intervals following {EMS} arrival time (tEMS) and hospital arrival time (tHOS). The Weibull model was repeated with tSURV interval-censored to reflect uncertainty about the exact time of death, using an imputation method to accommodate interval censoring along with TVC. Results {FARS} contained records for 92,718 persons with fatal or incapacitating injuries, and NASS/CDS contained 5517 (weighted population of 642,716) with incapacitating injuries. All models associated mortality with increasing age, male sex, belt nonuse, higher speeds, and vehicle rollover. The interval-censored model associated {EMS} intervention with a beneficial effect until tEMS + 30 min, but not thereafter; hospital intervention was associated with a strongly beneficial effect that increased with time. Rural location was associated with a higher baseline hazard; a 50% reduction in rural prehospital time would theoretically reduce 4-h mortality by about 7%. Conclusion Rural/urban disparity in crash mortality is mostly independent of time delays and {EMS} effects. However, survival models with {TVC} support clinical intuition of a “golden hour” in {EMS} care, and the importance of timely transport to a hospital.

Keywords: Emergency medicine

Traffic crashes have become the fifth leading cause of burden of diseases and injuries in China. More importantly, it may further aggravate the degree of health inequality among Chinese population, which is still under-investigated. Based on a nationally representative data, we calculated the concentration index (CI) to measure the socioeconomic inequality in traffic-related disability (TRD), and decomposed {CI} into potential sources of the inequality. Results show that more than 1.5 million Chinese adults were disabled by traffic crashes and the adults with financial disadvantage bear disproportionately heavier burden of TRD. Besides, strategies of reducing income inequality and protecting the safety of poor road users, are of great importance. Residence appears to counteract the socioeconomic inequality in TRD, however, it does not necessarily come to an optimistic conclusion. In addition to the worrying income gap between rural and urban areas, other possible mechanisms, e.g. the low level of post-crash medical resources in rural area, need further studies. China is one of the developing countries undergoing fast motorization and our findings could provide other countries in similar context with some insights about how to maintain socioeconomic equality in road safety.

Keywords: Traffic-related disability

Abstract Over 350,000 families have been evicted from their homes since Spain's property market crashed in 2008. The response of Spanish civil society has been the emergence of a networked social movement, Plataforma de Afectados por la Hipoteca (PAH; the Spanish Mortgage Victims Group), to stop the evictions and change applicable legislation. This paper uses social movement theory and the travel of ideas metaphor from organization theory to understand how the {PAH} movement and its practices and tactics, originally born in Barcelona in 2009, have successfully spread to over 160 cities and stopped over 1135 evictions throughout the country. We argue that the ability of networked social movements to quickly replicate has fuelled their power to resist, protest, and induce change. We contend that the fast growth of networked social movements in Global North and South cities, is fuelled by its ability to create a hybrid space between communication networks and occupied urban space in which face-to-face assemblies and protests take place.

Keywords: Networked social movements

Crash rates based on drivers, driver-kilometres, and driver-days in the denominator were compared, using survey estimates of time and distance driven and the annual frequency of traffic crashes in Ontario. Rates by age, sex, and region were computed for all crashes and for crashes resulting in injury or fatality. Young male drivers remained at high risk for all types of denominator; older women had high rates when distance was included in the denominator. When time spent driving was substituted, men and women drivers over 60 had very similar rates. For comparisons of rural residents with urban and northern residents, time and distance give equivalent results. These findings suggest that apparent differences in crash risk per kilometre, whether for older women or for urban drivers, is explained by differences in typical driving speed and environment. Exposure time is better than distance to explain crash risk among drivers and regions with very different driving patterns and environments.

Background This study aims to examine factors associated with variation in crash-related hospitalization costs for young adults in New South Wales (NSW), Australia with a particular focus on types of vehicle occupant, rurality of residence and socioeconomic status (SES). Methods Data on patients aged 17–25 years, admitted to public hospitals due to a crash during July 2000–June 2007 were extracted from the {NSW} Health Admission Collection database. The hospitalization cost of each admission was calculated based on published charges for specific Australian Refined-Diagnosis Related Groups (AR-DRG). Multivariable analyses using generalized estimating equations were used to estimate costs by vehicle occupant type (driver, passenger and other occupants), rurality of residence (urban, regional and rural areas) and {SES} (low, moderate and high {SES} areas). Results During 2000–2007, there were 11,892 crash-related hospitalizations involving young adults, aged 17–25 years, in NSW. These cost the health sector about A87.6 million or on average, A7363 per hospitalization (mean length of stay (LOS) 5.3 days). Compared to drivers, passengers had significantly longer {LOS} (&lt;0.01) as well as higher hospitalization costs (p = 0.04). Regional and rural young adults had significantly longer {LOS} and higher hospitalization costs compared to urban young adults (p &lt; 0.05). Compared with young adults from high {SES} areas, young adults from moderate {SES} areas had significantly higher costs (p = 0.02), whilst the higher costs for young adults of low {SES} areas was borderline significant (p = 0.06), although differences in {LOS} by {SES} were not significant. Conclusion Annually, young adults’ crashes in {NSW} were estimated to cost the health sector at least A14.6 million between 2001 and 2007. The higher hospitalization costs and {LOS} for young adults living in regional and rural vs. urban areas, and those living in moderate and low {SES} vs. high {SES} areas partly reflects the severity of these crashes and challenges for treatment. Based on these findings, a strong economic argument can be made for targeting prevention strategies to young people living in rural and low {SES} areas. The area variations in costs also suggest some scope for policy makers to consider potentially more efficient ways of targeting both treatment and preventative programmes.

Keywords: Motor vehicle injury

Motorcycles are frequently used in middle- and low-income societies. They are often involved in crashes, and account for a noticeable percentage of fatalities secondary to crashes. Comparing motor-vehicle occupants and motorcycle riders, the present study examined the survival hazard of crash injuries with respect to road environmental factors (i.e., area, road type, and location). We investigated the effects of such factors on survival and survival time after crashes via a binary logistic regression analysis and a Cox proportional hazard regression analysis, respectively. Results indicated that, for both motor-vehicle occupants and motorcycle riders, the fatal prevalence, occurrence likelihood, and risk based on time were decreased in urban areas and elevated on highways. The three indexes were also higher for motor-vehicle occupants on non-straight or non-level roadway sections. The prevalence of death on local roads and at intersections was relatively higher for motorcycle riders compared to motor-vehicle occupants. Speed may contribute to the survival hazard with respect to road environment factors. Speed management initiatives account for hazardous roadway, curve alignment re-examination, and increased traffic enforcement density are suggested. Collaboration among the roadway authorities, vehicle industry, and medical systems for a timely rescue is also advised. In addition, the attention to crashes at intersections and on local roads is a promising intervention for motorcycle riders.

Keywords: Survival analysis

Abstract Ramp vicinities are arguably the known black-spots on urban expressways. There, while maintaining high speed, drivers need to respond to several complex events such as maneuvering, reading road signs, route planning and maintaining safe distance from other maneuvering vehicles simultaneously which demand higher level of cognitive response to ensure safety. Therefore, any additional discomfort caused by traffic dynamics may induce driving error resulting in a crash. This manuscript presents a methodology for identifying these dynamically forming hazardous traffic conditions near the ramp vicinities with high resolution real-time traffic flow data. It separates the ramp vicinities into four zones – upstream and downstream of entrance and exit ramps, and builds four separate real-time crash prediction models. Around two year (December 2007 to October 2009) crash data as well as their matching traffic sensor data from Shibuya 3 and Shinjuku 4 expressways under the jurisdiction of Tokyo Metropolitan Expressway Company Limited have been utilized for this research. Random multinomial logit, a forest of multinomial logit models, has been used to identify the most important variables. Finally, a real-time modeling method, Bayesian belief net (BBN), has been employed to build the four models using ramp flow, flow and congestion index in the upstream and flow and speed in the downstream of the ramp location as variables. The newly proposed models could predict 50%, 42%, 43% and 55% of the future crashes with around 10% false alarm for the downstream of entrance, downstream of exit, upstream of entrance and upstream of exit ramps respectively. The models can be utilized in combination with various traffic smoothing measures such as ramp metering, variable speed limit, warning messages through variable message signs, etc. to enhance safety near the ramp vicinities.

Keywords: Real-time crash prediction model

The focus of this paper is twofold: (1) to examine the non-linear relationship between pedestrian crashes and predictor variables such as demographic characteristics (population and household units), socio-economic characteristics (mean income and total employment), land use characteristics, road network characteristics (the number of lanes, speed limit, presence of median, and pedestrian and vehicular volume) and accessibility to public transit systems, and (2) to develop generalized linear pedestrian crash estimation models (based on negative binomial distribution to accommodate for over-dispersion of data) by the level of pedestrian activity and spatial proximity to extract site specific data at signalized intersections. Data for 176 randomly selected signalized intersections in the City of Charlotte, North Carolina were used to examine the non-linear relationships and develop pedestrian crash estimation models. The average number of pedestrian crashes per year within 200 feet of each intersection was considered as the dependent variable whereas the demographic characteristics, socio-economic characteristics, land use characteristics, road network characteristics and the number of transit stops were considered as the predictor variables. The Pearson correlation coefficient was used to eliminate predictor variables that were correlated to each other. Models were then developed separately for all signalized intersections, high pedestrian activity signalized intersections and low pedestrian activity signalized intersections. The use of 0.25 mile, 0.5 mile and 1 mile buffer widths to extract data and develop models was also evaluated.

Keywords: Pedestrian

This paper examines the impact of personal and environmental characteristics on severity of injuries sustained in pedestrian–vehicle crashes using a generalized ordered probit model. The data covers 2000–2004 of pedestrian–vehicle crashes taken from police incident reports for Baltimore City and supplemented with local land use, urban form and transportation information specific to the individual crash locations. The results on personal and behavioral variables confirm previous findings. Women pedestrians involved in crashes tend to be injured less frequently than their male counterparts; children have an increased likelihood of sustaining injuries and older persons are more likely to be fatally injured. Pedestrians who cross against the traffic signal, are not in a crosswalk and are involved in a crash after dark are associated with greater injury risk. Of the built environment policy variables of interest, transit access and greater pedestrian connectivity, such as central city areas, are significant and negatively associated with injury severity. These results suggest that the environmental conditions should be given more scrutiny and be an important consideration when evaluating and planning for pedestrian safety.

Keywords: Pedestrian

This study examined the small area variation in motor vehicle crash fatality rates in the province of Alberta, Canada. Motor vehicle crash fatality rates per 100,000 population (1995–1997, inclusive) were determined for five geographic areas in the province. The rates showed substantial, statistically significant variation across areas, with fatality rates lowest in the urban areas of Calgary and Edmonton, and highest in the rural areas (south, central, and northern Alberta). Examination of area-level predictors—population density, impaired driving citation rates, education level, unemployment levels, and ethnicity—showed that population density and impaired driving rates were associated with motor vehicle crash fatality rates. There was a five-fold difference in annual motor vehicle crash fatality rates between rural (22.9/100,000) and urban areas (4.4/100,000), whereas annual impaired driving rates were around 1.8% in rural areas, compared with 0.6% in urban areas. Because of multicollinearity problems, it was not possible to estimate a multivariable Poisson regression model. In conclusion, rural areas in the province of Alberta demonstrate a significantly higher motor vehicle crash fatality rate, compared with urban areas.

Keywords: Traffic accidents

The rates of motor-vehicle crash mortality are highest among American Indians and Alaska Natives, compared to other ethnic groups. The aim of this study was to compare risk factors for motor-vehicle crashes and occupant injuries between rural and urban American-Indian (AI) drivers, and between rural {AI} and non-AI rural drivers. A statewide traffic-accident database was linked to the Indian Health Service patient-registration database to identify crashes that involved American-Indian drivers. Using a cross-sectional design, crashes occurring in a two-county region during 1989 and 1990 were studied. A total of 9329 motor-vehicle crashes involving 16,234 drivers and 6431 passengers were studied. Two percent of drivers were American Indian. Compared to American-Indian drivers in urban crashes, rural crashes involving American-Indian drivers were more likely to result in injury or death (38% vs 64%, p < 0.001). The difference in risk for crashes between urban and rural non-AI drivers was not as high (42% vs 33%). Only 44 percent of rural American-Indian motor-vehicle occupants reported wearing seat belts, compared to 70 percent of urban American-Indian occupants (p < 0.05). Rates of driver alcohol impairment, as assessed by the police, were much higher among {AI} drivers and highest among rural {AI} drivers. We conclude that, compared to non-American-Indian drivers, {AI} drivers are less likely to be restrained and more likely to be alcohol-impaired at the time of the crash. These risks are higher among rural {AI} drivers than urban {AI} drivers.

Keywords: Indians—North American

The prevailing risk of traffic fatalities is much larger in rural areas compared to urban areas. A number of explanations have been offered to explain this including road design, emergency medical service proximity, and human factors. This research explored the potential contribution of rural driver attitudes that may underlie the increased fatal crash risk in rural environments. This analysis examined differences between rural and urban drivers in terms of self-reported risk taking for driving behaviors associated with fatal crashes and attitudes toward safety interventions using a large-scale survey. The results suggested that rural drivers engage in riskier behavior, such as not wearing seatbelts, because they have lower perceptions of the risks associated with such behaviors. Results also suggested that vehicle type (e.g., pickup trucks versus passenger vehicles) may be related to seatbelt compliance and frequency of driving under the influence of alcohol. Rural drivers perceived the utility of government-sponsored traffic safety interventions to be lower than their urban counterparts. This study provides insights into the role of the human factor in rural fatal crashes and provides policy suggestions for developing safety interventions that are designed with respect to the psychosocial factors that define the rural culture.

Keywords: Rural

Introduction Roadway safety is a major concern for the general public and public agencies, as roadway crashes claim many lives and cause substantial economic loss each year. In Iran, a large number of vehicles are involved in road accidents each year, which cause many deaths and extensive property damage; such accidents are among the major causes of death and disability in the country. Method: To reduce roadway accidents, the factors that affect the occurrence and severity of accidents should be scrutinized to prevent or reduce their effect. The method that many researchers have adopted to determine the effective parameters surrounding road accidents in recent years is through statistical modeling of accidents. In this article, the role of different kinds of vehicles in traffic flow are investigated separately in terms of the likelihood of crashes on urban highways, and the vehicles are divided into three groups: passenger cars, heavy vehicles, and light non-passenger car vehicles. Poisson and negative binomial (NB) regression models were applied to model the accidents in this research, which were categorized into two groups: no injury (property damage only) accidents and more severe (injury and fatal) accidents. Results: Ultimately, we conclude that light non-passenger car vehicles (i.e., taxis and motorcycles) play the largest role in the occurrence of crashes on urban highways for both types of accidents.

Keywords: No injury accidents

As in other parts of the Western world, there is concern in New Zealand about increasing popularity of motorcycles because of potential increases in road trauma. This study sought to identify important factors associated with increased risk for motorcyclists to inform potential policy approaches to reduce motorcyclist injury, such as changes to motorcyclist licensing, training and education. Using data extracted from a register of all New Zealand licensed motor vehicles that were matched to crash data, statistical models were fitted to examine patterns of motorcycle risk in comparison with small cars. These showed generally elevated risks for motorcyclists compared to cars, but particularly elevated risks for motorcycle owners aged in their 20s or who lived in more urbanised settings. In crashes, motorcyclists have little protection from injury, putting the motorcyclist at high risk of injury. When comparing new motorcycles with new cars, the odds of fatal or serious injury to a motorcycle rider involved in an injury crash were almost eight times the odds for a car driver.

Keywords: Injury

Objectives. Historically, motor vehicle crash (MVC)-related mortality is higher in rural areas than in urban areas. The authors evaluated whether the difference in rural and urban {MVC} deaths is persisting, and whether the frequency of patients being found dead at the scene, particularly in rural areas, is increasing. Methods. Fatal Accident Reporting System (FARS) data for 1-977 through 1996 were reviewed. The authors determined the frequency with which crash deaths occurred, and calculated population-based and vehicle-miles-traveled-based crash death rates. They compared rates for urban and rural areas. Results. A total of 875,405 crash deaths were included in the analysis. Both population-based and -vehicle-miles-traveled-based {MVC} deaths have decreased over the last 20 years, but rural rates remain significantly higher than urban rates. Dead-at-scene rates may be increasing, and the rural dead-at-scene rate is higher than the urban rate. Conclusion. While {MVC} death rates are declining, the rural {MVC} death rate is still higher than the urban rate. Although these data may indicate some positive movement in the area of MVC-related deaths, differences in the rural and urban rates and the number of patients found dead on-scene remain as issues that require attention. {PREHOSPITAL} {EMERGENCY} {CARE} 2000;4:7-13

Keywords: accidents

Previous research has found that only older drivers with low annual driving mileages had a heightened crash risk relative to other age groups. These drivers tend to drive mainly in urban areas, where the prevalence of complex traffic situations increases crash risk. However it might also be that some drivers may have reduced their driving due to perceived or actual declines in driving fitness. This paper uses Canadian and Australian data from the Candrive/Ozcandrive older driver study to investigate the association between annual driving distances and a set of driving-related factors, including fitness to drive. All drivers in the Candrive/Ozcandrive older driver cohort study were allocated to one of three groups according to their self-reported annual driving distances: <5001 km; >5000 and <15,000 km; and 15,000 km or greater. Relationships between these driving-distance categories and: (a) self-reported crash data; (b) various Year 1 ‘fitness to drive’ performance measures; and (c) self-perceptions of driving ability and of comfort while driving, were determined. Results confirmed the previously reported association between low mileage and heightened crash risk. Further, low mileage drivers performed relatively poorly on a wide range of performance measures, perceived their own driving ability as lower, and reported lower comfort levels when driving in challenging situations, compared to the higher mileage drivers. In most instances, these differences were statistically significant. The paper provides further evidence that the so-called ‘older driver problem’ is most pertinent to low mileage drivers, and that this is due in part to low mileage drivers tending to have reduced fitness to drive. This higher risk group represented a fairly small proportion of the sample in this study.

Keywords: Older drivers

During the last few decades, the two-fluid model and its two parameters have been widely used in transportation engineering to represent the quality of operational traffic service on urban arterials. Catastrophe models have also often been used to describe traffic flow on freeway sections. This paper demonstrates the possibility of developing a pro-active network screening tool that estimates the crash rate using a stochastic cusp catastrophe model with the two-fluid model's parameters as inputs. The paper investigates the analogy in logic behind the two-fluid model and the catastrophe model using straightforward graphical illustrations. The paper then demonstrates the application of two-fluid model parameters to a stochastic catastrophe model designed to estimate the level of safety on urban arterials. Current road safety management, including network safety screening, is post-active rather than pro-active in the sense that an existing hotspot must be identified before a safety improvement program can be implemented. This paper suggests that a stochastic catastrophe model can help us to become more pro-active by helping us to identify urban arterials that currently show an acceptable level of safety, but which are vulnerable to turning into crash hotspots. We would then be able to implement remedial actions before hotspots develop.

Keywords: Catastrophe model

Traffic safety studies have underscored the hazardous conditions of pedestrians in the United States. This situation calls for increased public awareness of the pedestrian safety issue and better knowledge of the main factors contributing to traffic hazard for urban pedestrians. The purpose of this spatial epidemiology research is to gain greater insights into the geographic dimension exhibited by the intensity of traffic collisions involving urban pedestrians. Pedestrian crashes are studied in Buffalo, {NY} for years 2003 and 2004. Factors of hazard intensity are determined and compared for three age cohorts as well as for collisions occurring at intersections versus mid-block locations. Physical road characteristics and density of development, as well as socio-economic and demographic variables and potential trip attractors are examined. Spatial regression models are used to account for spatial dependencies. Econometric analysis underscores that all classes of environmental factors tested are significant drivers of pedestrian traffic hazard intensity. Results of the geographic analysis indicate that young and adult pedestrian traffic hazard intensities follow rather distinct logics. In addition, intersection and mid-block crashes differ by their socio-economic correlates, as well as their spatial distribution in the urban fabric.

Keywords: Pedestrian collision

This paper introduces dynamic time series modeling in a Bayesian framework to uncover temporal patterns in highway crashes in Connecticut. Existing state sources provide data describing the time for each crash and demographic attributes of persons involved over the time period from January 1995 to December 2009 as well as the traffic volumes and the characteristics of the roads on which these crashes occurred. Induced exposure techniques are used to estimate the exposure for senior and non-senior drivers by road access type (limited access and surface roads) and area type (urban or rural). We show that these dynamic models fit the data better than the usual {GLM} framework while also permitting discovery of temporal trends in the estimation of parameters, and that computational difficulties arising from Markov Chain Monte Carlo (MCMC) techniques can be handled by the innovative Integrated Nested Laplace Approximations (INLA). Using these techniques we find that while overall safety is increasing over time, the level of safety for senior drivers has remained more stagnant than for non-senior drivers, particularly on rural limited access roads. The greatest opportunity for improvement of safety for senior drivers is on rural surface roads.

Keywords: Dynamic generalized linear models

The purpose of this study was to determine if emergency medical service (EMS) personnel could take instant photographs of motor vehicle damage at crash scenes depicting the area and severity of damage of the crash under adverse weather conditions, in different lighting, and quickly enough so as not to interfere with patient care. This prospective multicenter trial involved 35 ambulances responding to motor vehicle crash scenes in rural, suburban, and urban areas in five centers in four states. Emergency medical technicians (EMTs) reported their experience implementing a protocol for use of an instant camera to photograph vehicle damage at crash scenes. Time reported by {EMTs} to take the photographs was 1 minute or less in 204 of 288 (70.9%) of motor vehicle crashes and 2 minutes or longer in 12 of 288 (4.2%) of motor vehicle crashes. From one {EMS} agency in the study, 48 scene times during which photographs were taken were, on average, 1.5 minutes shorter than 48 scene times immediately before implementation of on-scene crash photography. Photographs were taken in different weather and lighting conditions. {EMTs} reported they were able to determine both area and severity of damage in 260 of 290 (92.5%) crash photographs, but they were unable to determine area and severity of damage in only 2 of 290 (0.7%) crash photographs.

Keywords: Traffic accidents

To identify factors influencing severity of injury to older drivers in fixed object–passenger car crashes, two sets of sequential binary logistic regression models were developed. The dependent variable in one set of models was driver injury severity, whereas for the other it was the crash severity (most severe injury in the crash). For each set of models, crash or injury severity was varied from the least severity level (no injury) to the highest severity level (fatality) and vice versa. The source of data was police crash reports from the state of Florida. The model with the best fitting and highest predictive capability was used to identify the influence of roadway, environmental, vehicle, and driver related factors on severity. Travel speed, restraint device usage, point of impact, use of alcohol and drugs, personal condition, gender, whether the driver is at fault, urban/rural nature and grade/curve existence at the crash location were identified as the important factors for making an injury severity difference to older drivers involved in single vehicle crashes.

Keywords: Older drivers

The present article deals with individual cyclists’ probabilities of severe injury or death from a bicycle accident. We use an empirical Bayesian method to conduct an analysis of the fatal/severe probability distribution of a bicycle accident, at the level of individuals, in dense French urban areas. Among intuitive results, it is found that wearing a helmet lowers the average probability of such a crash; it is also shown that young bicyclists are, on average, more exposed to severe and/or fatal crashes. Finally, the results highlight a decrease of attention paid by all types of road users following road infrastructure improvements in favor of cyclists.

Keywords: Road safety for cyclists

Abstract Iran has a high traffic fatality rate and a substantial proportion of those killed on the road are adolescents. The aim of the present study was to examine the relationship between dimensions of religiosity and the on-road behaviour of adolescents as pedestrians, cyclists and other non-driving activities. A total of 1111 students attending secondary schools in Tehran (Iran) completed the Adolescent Road User Behaviour Questionnaire (ARBQ) and the Duke University Religion Index (DUREL). This study found that adolescents who participated less often in private religious activities were more likely to be: male, have relatives or friends who had been killed in a road collision, previously involved in a road crash themselves and engaged more often in dangerous playing on the road. Adolescents reporting higher levels of religious attendance and intrinsic religiosity were more likely to be: male, without a traffic accident history, younger, from public schools, studying at schools in large urban areas and more frequently engaged in planned protective behaviours. Adolescents with higher involvement in intrinsic religiosity tended to be those: without an accident history, who did not have relatives or friends that had been killed in a crash and who engaged less frequently in unsafe road crossing behaviour. The findings of this study indicate that the different dimensions of religiousness are related to adolescents’ behaviour on the road. Thus, it appears that religion may have a role to play in improving the road safety of adolescents in Iran.

Keywords: Religion

Abstract Ambulance crashes are a significant safety issue both to the {EMTs} and to patients transported in the vehicle. Safety issues are dependent on the environment and may be different in rural and urban settings. Ambulance crashes reported to the State {EMS} bureau during the years of 1993 to 1997 were evaluated. Counties with >250,000 population were considered urban. State population was 2 million urban and 2.8 million rural. Two investigators determined first if the crash was urban or rural. Outcome information was extracted on the degree of injury, citations given, and information on the ambulance and other vehicle condition. In addition, independent variables of weekend versus weekday, day versus night, posted speed, weather, road condition (wet versus dry), intersections, and use of seat belts were extracted. Results were compared using a 2-tailed Chi-square or Fisher's exact with significance at P <.05. Relative risks and 95% confidence intervals were calculated for each variable. There were a total of 183 Ambulance crashes, 115 urban (19/million pop/yr), and 68 rural (8/million pop/yr). Significantly lower percentage of injury crashes occurred in the urban setting (OR = 0.49, 95% {CI} = 0.24 to 0.98) with fewer of these considered “severe” (OR = 0.0, 95% {CI} = 0.0 to 0.73). Citations were more likely to be issued to the urban ambulance driver (OR = 4.95, 95% {CI} = 1.09 to 45.70) and the other urban vehicle driver (OR = 3.65, 95% {CI} = 1.37 to 11.31). However, the urban ambulance was less likely to be damaged (OR = 0.24, 95% {CI} = 0.10 to 0.55), disabled (OR = 0.41, 95% {CI} = 0.20 to 0.84), or towed (OR = 0.40, 95% {CI} = 0.20 to 0.83). In the urban setting fewer vehicles were traveling in areas with posted speeds >54 mph (OR = 0.24, 95% {CI} = 0.06 to 0.78) and nonrestrained people were less likely to be injured (OR = 0.28, 95% {CI} = 0.06 to 1.25). For injured persons there was no difference in independent variables in the urban versus rural settings. Although the rate of ambulance injuries was greater in the urban environment, the severity of the injuries was worse in the rural environments where crashes occurred at higher posted speeds. In the rural setting nonrestrained passengers were more likely to be injured. (Am J Emerg Med 2001;19:52-56. Copyright © 2001 by W.B. Saunders Company)

Keywords: EMS

There has been considerable research conducted in recent years into establishing relationships between crashes and various traffic flow characteristics for freeway segments. Most of the research has focused on determining the relationship between crashes and highway traffic volumes, while little attention has been focused on the relationships of vehicle density, level of service (LOS), vehicle occupancy, V/C ratio and speed distribution. Despite overall progress, there is still no clear understanding about the effects of different traffic flow characteristics on safety. In fact, several studies reviewed in this work were found to have methodological limitations. These include using predictive models with a normal error structure, aggregated crash rates, and inadequate functional forms for the data at hand. The original research on which this paper is based is aimed to determine the statistical relationship using commonly applied predictive models (i.e., functional forms) between crashes and hourly traffic flow characteristics, such as traffic volume, vehicle density and V/C ratios, for rural and urban freeway segments respectively. To accomplish this objective, predictive models have been developed from data collected on freeway segments located in downtown and outside of Montreal, Quebec. Three different functional forms are evaluated. The results show that predictive models that use traffic volume as the only explanatory variable may not adequately characterize the accident process on freeway segments. Functional forms that incorporate density and V/C ratio offer a richer description of crashes occurring on these facilities, whether they are located in a rural or urban environment. Finally, separate predictive models for single- and multi-vehicle crashes should be developed rather than one common model for all crash types.

Keywords: Predictive models

Abstract There are factors that impact traffic safety and the number of accident-related fatalities, such as street users, environment, road design and vehicle characteristics, but there have been limited studies that examine the relationship between street network factors and traffic-related crashes and fatalities at the city level. Therefore, this paper focused on this relationship by introducing urban street network variables, such as blocks per area, nodes per selected areas and length of roads and motorways, as independent variables and the number of fatalities as the dependent variable. This study used Open Street Maps (OSM) and International Association of Public Transport (UITP) data from 20 cities around the world. The number of blocks per area and nodes per selected areas resulted from modifying and analyzing {OSM} maps in ArcGIS software. The strength of the relationship in this study was found using generalized linear modeling (GLM). The findings of this research indicated that increases in fatalities are correlated with an increasing number of blocks per area, number of nodes per selected areas and length of the motorways.

Keywords: Urban transportation safety

Five urban, uncontrolled T-intersections known to be motorcycle crash ‘black spots’ were monitored using instrumentation and a roadside observer. Two sets of twelve-hour observations were collected for each site (N ≈ 100,000). Instrumentation recorded the ‘events’ of vehicles passing to measure, speed, direction, lane position, vehicle type (broadly characterised) and headway. Observers further recorded times of bicycle events, type of motorcycle (scooters or motorcycles), the behaviour of motorcycles and the use of ‘high conspicuity’ gear such as clothing or helmets. Results establish that motorcycles travel around 10% faster than the other traffic (car mean speed = 34.97 km/h), with motorcycles travelling on average 3.3 km/h faster than cars. Motorcycles were 3.4 times more likely to be exceeding the speed limit than cars. Similar results are described for scooters. Also examined are the influences on mean speeds such as the time of day, the presence of a car at the t-intersection, and the influence of free headway. The results are compared for robustness across locations and days. It is concluded that in urban areas motorcycles are travelling significantly faster than other traffic. These findings are discussed against a concern to reduce motorcycle crashes by improving conspicuity and previous research that implicates a ‘looked-but-failed-to-see’ effect for car drivers.

Keywords: Motorcycles

Abstract The present research investigated the prevalence of driver engagement in secondary tasks and whether there were any differences by age and gender, as well as day of the week and time of the day. Two independent researchers observed 6578 drivers at nine randomly selected urban locations in Girona, Spain. Nearly 20% of the drivers observed were engaged in some type of secondary task, with the most common being: conversing with a passenger (11.1%), smoking (3.7%) and talking on a handheld mobile phone (1.3%). Surprisingly there were no differences by gender, but there were age-related differences with younger drivers being more frequently observed engaged in a number of different types of secondary tasks while driving (i.e. drinking, talking on a handheld mobile phone, and texting or keying numbers). Logistic regression showed that younger drivers, and to a lesser extent middle-age drivers, were significantly more likely to be observed engaged in a technological distraction than older drivers. Conversely, non-technological distractions were significantly predicted by day of the week, time of the day and location. A substantial number of the drivers observed in this study were putting themselves at an increased risk of becoming involved in a crash by engaging in non-driving related tasks at the same time as driving. Furthermore, the higher crash rate among young drivers may be partially accounted for by their more frequent engagement in some types of secondary tasks while driving.

Keywords: Cell phone

Motor vehicle crashes are the leading cause of death and a leading cause of non-fatal injury for teenagers in the United States. Understanding teen crashes requires a good measure of crash risk. The measure of exposure that is used in the calculation of risk estimates determines what information the resulting rates and rate ratios provide and the conclusions that can be drawn about teen driver crash risk. The purpose of this study is to provide an initial description of three measures of individual-level exposure to driving for 16–17-year-olds in the state of Michigan, using data from the state-wide Michigan Travel Counts survey conducted in 2004 and 2005. The total miles, minutes, and trips driven within the 48-h survey period were calculated for each respondent using self-reported measures and geo-spatial mapping. Young drivers who worked and those with greater access to a vehicle drove significantly more than their peers who did not work and those who had less access to a vehicle. Those from urban residences spent more time driving than those from rural residences. All 16–17-year-olds drove substantially more during the day than at night, and on their own than with passengers. There was little difference in overall driving exposure and driving behavior between young men and young women. This study provides an initial description of driving exposure and behavior for a population for which there is very little specific information about amounts and patterns of individual driving exposure. The relationship between individual driving exposure and risk of motor vehicle crash, injury or fatality requires further investigation.

Keywords: Teen driving

For North Dakota teens, three of every four deaths are from motor vehicle crashes. Injury crash records for teen drivers were studied to gain insight regarding driver, vehicle, and road factors for public safety policy and program discussions. Results show 14-year-old drivers are three times more likely to die or be disabled in an injury crash than 17-year-old drivers, and that male drivers are 30% less likely to incur severe injury. As expected, seat belt use is a critical factor in severe injury avoidance. The likelihood for death or disablement is 165% greater for unbelted teen drivers than for those who are properly belted. In addition, rural and gravel roads pose a risk. Teens are six times more likely to be severely injured in crashes on rural roads than on urban roads. Findings suggest that an increased licensing age and seat belt emphasis may reduce teen traffic injuries in the state. In addition, more information on exposure should be attained to better understand rural and gravel road as risks.

Keywords: Teens

Pedestrian–vehicle crashes represent a small percentage of all Virginia crashes (less than 2% over the past 10 years). However, approximately 10% of crash fatalities are pedestrians. We analyzed pedestrian crash trends from 1990–1999 and investigated variables believed to predict these crashes, such as location (urban versus rural setting), sex, age, pedestrian drinking, driver drinking, driver violation, and time of day. A logistic regression analysis, controlling for year, found all of these variables significantly predicted the odds of dying versus being injured in a pedestrian crash. The typical fatality victim was an older male who had been drinking and was walking in a rural area between 12:00 and 5:59 a.m. A driver who had been drinking but would not be cited for a violation more likely struck this pedestrian. Crash data do not tell us about the knowledge drivers and pedestrians have regarding pedestrian laws, and how such knowledge suggested typical self-reported behaviors. Thus, we conducted a telephone survey of licensed Virginia drivers to assess such self-reported knowledge and behaviors. Most respondents reported knowing and following state laws regarding driver yielding and walking across streets. However, we found one area of particular concern. Respondents tended to believe pedestrians had the right-of-way at all times even when not crossing at crosswalks or intersections when Virginia law does not yield right-of-way to pedestrians in all cases. Virginia does not assign right-of-way in all cases to any group; rather the context determines who may proceed while others yield. Additional analyses from the crash trends and survey are reported in the text. The authors also draw parallels between their {US} research and that of the international community.

Crash statistics that include the blood alcohol concentration (BAC) of vehicle operators reveal that crash involved motorcyclists are over represented at low {BACs} (e.g., ≤0.05%). This riding simulator study compared riding performance and hazard response under three low dose alcohol conditions (sober, 0.02% BAC, 0.05% BAC). Forty participants (20 novice, 20 experienced) completed simulated rides in urban and rural scenarios while responding to a safety-critical peripheral detection task (PDT). Results showed a significant increase in the standard deviation of lateral position in the urban scenario and {PDT} reaction time in the rural scenario under 0.05% {BAC} compared with zero alcohol. Participants were most likely to collide with an unexpected pedestrian in the urban scenario at 0.02% BAC, with novice participants at a greater relative risk than experienced riders. Novices chose to ride faster than experienced participants in the rural scenario regardless of BAC. Not all results were significant, emphasising the complex situation of the effects of low dose {BAC} on riding performance, which needs further research. The results of this simulator study provide some support for a legal {BAC} for motorcyclists below 0.05%.

Keywords: Blood alcohol concentration (BAC)

Abstract Property-led arts development (PAD) is central to urban policy and planning. The demand for physical arts infrastructure runs parallel with the public call for arts nonprofits to act more entrepreneurial in shaping and re-imaging urban space. Increasingly, these groups have become active property developers negotiating the risks and rewards of land development rather than remaining passive fundraisers of bricks and mortar campaigns. This shift in organizational identity raises questions about whether the politics of urban arts development have changed. This study asks four questions: (1) how are nonprofit arts organizations becoming more entrepreneurial in property development, (2) how are nonprofit arts organizations reshaping the urban landscape through development partnerships, (3) how are nonprofit arts developers responding to the 2008 economic crash, and (4) how does {PAD} align with new thinking on downtown development alliances? This research explores the innovative but failed land development deal between the Seattle Art Museum and the now-defunct Washington Mutual to build a joint tower in the central business district. Their atypical private/nonprofit partnership changed Seattle’s downtown landscape through flexible ownership structures, generous planning incentives and off-budget municipal maneuvers. The lauded project turned sour when the homegrown financial institution collapsed, forcing the museum into debt with limited private or public sector solutions. While {SAM} overcame the immediate crisis, the case is a cautionary tale about the long-term risk of contemporary PAD. The case shows that innovative practices do not predetermine success. Further, the partnership study illuminates how contemporary arts investments reflect as well as contradict new thinking in urban politics literature about evolving patterns of influence in U.S. downtowns.

Keywords: Arts economic development

Road safety engineering can play an integral part in the prevention of whiplash injuries. While improvements to vehicle design can reduce the severity of whiplash injuries when a crash occurs, improvements to road safety can prevent whiplash-inducing crashes from occurring in the first place. Whiplash injuries are most commonly associated with rear end crashes. Unfortunately, rear end crashes are also the most common type of crash at urban signalized intersections, where the majority of crashes occur in British Columbia, Canada. The Insurance Corporation of British Columbia (ICBC), through the road improvement program, has been funding road improvements in order to reduce the frequency of collisions at high crash locations in British Columbia. Several road safety engineering countermeasures specifically targeted at rear end collisions have been researched and deployed. These countermeasures include simple and affordable solutions such as signal visibility enhancements, as well as complex and expensive solutions such as intersection geometric upgrades. When appropriately used, these countermeasures have proven to be extremely cost-effective in reducing the frequency of rear end collisions. Widespread application of signal visibility enhancements is now being pursued to further decrease the risk of rear end collisions and whiplash injuries. Costs are the direct cost of the {ICBC} portion of the investment and benefits are only those associated with reduced insurance claims over a 2-year period.

Keywords: Road safety

Two types of crashes are common on urban freeways: in-lane rear-end impacts with stopped or slowed vehicles and those where a vehicle leaves the roadway (and road shoulder) and impacts with obstacles outside traffic lanes. Crashes resulting in a fatal or severe injury to a vehicle occupant were identified from crash records in the regional office of the California Department of Transportation for the 1,500 miles of freeways in Los Angeles, Ventura, and Orange counties, California, for 1984 and 1985. Selected road characteristics were assessed and traffic-volume data obtained for these freeways to determine the relationship of these types of crashes to freeway features. Fatal- or severe-injury crash rates were highest for off-road crashes compared with in-lane crashes, with certain lanes having more frequent in-lane collisions and with a higher rate of in-lane crashes in freeway segments without a left shoulder. Off-road collisions were significantly more frequent in the absence of a right shoulder and on freeways with two or three lanes. Multivariate analyses that control for selected confounding factors such as traffic volume show similar findings including strong association with hour of crash.

Evaluation of crash-related injuries by medical specialists in hospitals is believed to be more exact than rather a cursory evaluation made at the crash scene. Safety analysts sometimes reach for hospital data and use them in combination with the police crash data. One issue that needs to be addressed is the, so-called, selectivity (or selection) bias possible when data used in analysis are not coming from random sampling. If not properly addressed, this issue can lead to a considerable bias in both the model coefficient estimates and the model predictions. This paper investigates pedestrian injury severity factors using linked police-hospital data. A bivariate ordered probit model with sample selection is used to check for the presence of the selectivity bias and to account for it in the {MAIS} estimates on the Maximum Abbreviated Injury Scale (MAIS). The presence of the sample selection issue has been confirmed. The selectivity bias is considerable in predictions of low injury levels. The pedestrian injury analysis identified and estimated several severity factors, including pedestrian, road, and vehicle characteristics. Male and older pedestrians were found to be particularly exposed to severe injuries. Rural roads and high-speed urban roads appear to be more dangerous for pedestrians, particularly when crossing such roads. Crossing a road between intersections was found to be particularly dangerous behavior. The size and weight of the vehicle involved in a pedestrian crash were also found to have an effect on the pedestrian injury level. The relevant safety countermeasures that may improve pedestrian safety have been proposed.

Keywords: Pedestrian safety

AbstractIntroduction Children aged 8- to 12-years-old (“tweens”) are at high risk for crash injury, and motor vehicle crashes are their leading cause of death. Method Data are presented from behavioral observations (N = 243), surveys (N = 677), and focus groups (N = 26) conducted with tweens attending four urban elementary schools in Virginia. The populations assessed were predominantly Black (77.9%) and economically disadvantaged (61.9%). Results Focus groups revealed a number of inconsistencies in and misconceptions about safety practices. Among the 677 tweens who completed anonymous surveys, the majority (58.1%) reported wearing their seat belts “not very much at all” or “never.” Many students (47.8%) reported usually sitting in the front seat or sitting in the front and back seats equally. This is despite the fact that most (92.0%) knew that the back seat was the safest place to sit. Of the 243 tweens observed in vehicles, 65.0% were unrestrained and 60.1% were seated in the front passenger seat. Impact on Industry Findings of this study shed light on the great disparity between the national rates for child safety practices and those of children living in an economically disadvantaged urban school district. Additional intervention programs that are culturally appropriate and specifically target this age group are needed.

Keywords: children

Abstract Connected Vehicle (CV) technology, formerly known as IntelliDrive, has emerged and is expected to provide unprecedented improvements in mobility. A recent study developed a cooperative vehicle intersection control (CVIC) algorithm for an urban intersection that does not require a stop-and-go style traffic signal and demonstrated significant mobility improvements over an actuated traffic signal control. This paper expanded the algorithm and implemented it to a corridor consisting of multiple intersections. In addition, this paper investigated sustainability aspects of the {CVIC} system for an urban traffic control system by applying surrogate safety assessment model (SSAM) and VT-Micro model to measure safety and environmental impacts, respectively. A simulation-based case study was performed on a hypothetical arterial consisting of four intersections with eight traffic congestion cases covering low to high volume conditions. When compared to the coordinated actuated control, the {CVIC} system dramatically reduced the total delay times for the volume cases considered (i.e., from 82% to 100% delay time savings observed). The {CVIC} system also reduced the number of rear-end crash events by 30–87% for the volume cases considered, indicating that safer driving conditions would be achieved with the {CVIC} system. Finally, the {CVIC} system contributed to improving the air quality (i.e., 12–36% {CO2} emission reduction) and saving fuel consumptions (11–37% of gas saving).

Keywords: Intelligent transportation system

More than 1 million motor vehicle crashes occur annually at signalized intersections in the USA. The principal method used to prevent crashes associated with routine changes in signal indications is employment of a traffic signal change interval — a brief yellow and all-red period that follows the green indication. No universal practice exists for selecting the duration of change intervals, and little is known about the influence of the duration of the change interval on crash risk. The purpose of this study was to estimate potential crash effects of modifying the duration of traffic signal change intervals to conform with values associated with a proposed recommended practice published by the Institute of Transportation Engineers. A sample of 122 intersections was identified and randomly assigned to experimental and control groups. Of 51 eligible experimental sites, 40 (78%) needed signal timing changes. For the 3-year period following implementation of signal timing changes, there was an 8% reduction in reportable crashes at experimental sites relative to those occurring at control sites (P=0.08). For injury crashes, a 12% reduction at experimental sites relative to those occurring at control sites was found (P=0.03). Pedestrian and bicycle crashes at experimental sites decreased 37% (P=0.03) relative to controls. Given these results and the relatively low cost of re-timing traffic signals, modifying the duration of traffic signal change intervals to conform with values associated with the Institute of Transportation Engineers’ proposed recommended practice should be strongly considered by transportation agencies to reduce the frequency of urban motor vehicle crashes.

Keywords: Traffic signal re-timing

Abstract China has long ranked first in the world in the number of road accidents and fatalities, approximately 30% of which occurred at urban intersections. Therefore, measuring intersection safety factors is essential to achieve effective correction countermeasures. A Root Cause Degree Procedure (RCDP) to measure intersection safety is proposed. The idea behind {RCDP} is to prevent the likelihood of a problem’s reoccurrence based on root cause analysis. It combines the {DEMATEL} (Decision Making Trial and Evaluation Laboratory) method and fuzzy logic to determine quantified measures. The root cause factor can be clearly visualised and differentiated using the Root Cause Degree (RCD) diagram. The factors with the largest {RCD} should be improved for greater benefit-cost ratio at limited traffic financial investment. The method uses the accident risk degree as an evaluation index based on risk analysis, which is independent of crash data, and is suitable for current incomplete crash data sets, such as those from developing regions of China. Additionally, the Shanghai municipality is used as an example for the pilot analysis. The current root cause factors in order of frequency of occurrence are clearance time, safety education, enforcement, the trajectory inside the intersection, crossing a refuge island, speeding, and the right turn control pattern. These factors should be corrected to improve safety performance. These results are consistent with actual traffic conditions according to current engineering practices, which indicates the feasibility of the proposed method.

Keywords: Intersection safety

AbstractBackground The number of inpatient admissions for proximal humerus fracture is increasing, but the factors that determine hospitalization are not well documented. We sought to identify predictors of hospital admission among individuals presenting to the emergency department (ED) with a fracture of the proximal humerus. Methods Using the Nationwide Emergency Department Sample for 2010 and 2011, an estimated 285 661 patients were identified and separated into those who were admitted to hospital (19%) and those who were discharged directly home (81%). Multivariable logistic regression modeling was used to identify independent predictors of hospital admission. Results Factors associated with admission included increasing age and Charlson comorbidity index, {ED} visit on a weekday, Medicare and Medicaid insurance, open fracture, injury due to motor vehicle crash, polytrauma, urban teaching hospital, and residence in the Northeast. The lowest ratio of hospital admission to home discharge was noted for uninsured patients (0.09). Discussion Factors unrelated to medical complexity such as insurance status, geographic region, timing of {ED} visit, and hospital type are associated with inpatient admission for proximal humerus fracture. Interventions to reduce variation in hospital admission and the influence of nonclinical factors merit attention. Level of Evidence Level II, prognostic study.

Abstract Currently, several efforts and strategies are used to reduce deaths in road accidents. However, only a few studies have considered the effectiveness of work travel mode choice on the number of accident-related fatalities at the city level. This study introduces a city-level (across cities) model to estimate the relationships between the number of deaths in road accidents (as the dependent variable) and several work travel mode choice indicators, including walking, cycling and public transport (as independent variables). Generalized linear modeling (GLM), which is a common technique for modeling crash data, was used to estimate this relationship. Data sets from various European cities were used to develop this city level model. Overall, the percentages of the journeys to work by public transport, motorcycle, bicycle and foot were effective variables in the model.

Keywords: Work travel mode choice

Abstract Normally, bars and restaurants are the preferred locations for drinking. Therefore, there is concern that the roads in bar and restaurant areas could have a higher probability of drink-drivers and alcohol-related road crashes. Many studies have been conducted to model the association between drinking locations and the prevalence of drink-driving, so that cost-effective enforcement strategies can be developed to combat drink-driving. In this study, a cluster analysis approach was applied to model the spatial–temporal variation of drink-driving distribution in Hong Kong. Six spatial–temporal clusters of drink-driving distribution emerged from the data: (i) bar and restaurant area, weekend-overnight; (ii) bar and restaurant area, other timespan; (iii) urban area, weekend-overnight; (iv) urban area, other timespans; (v) rural area, weekend-overnight; and (vi) rural area, other timespans. Next, separate zero-inflated regression models were established to identify the factors contributing to the prevalence of drink-driving for each of the six recognized clusters. The results indicated that drivers in rural areas tend to consume more alcohol than those in urban areas, regardless of the time period. In addition, both seasonal variation and vehicle class were found to determine the breath alcohol concentration (BrAC) levels among drivers.

Keywords: Drink-driving

Aim This study aims to better understand the patterns and factors associated with the use of emergency department (ED) services on high-volume and intensive (defined by high volume and high-patient severity) days to improve resource allocation and reduce {ED} overcrowding. Methods This study created a new index of “intensive use” based on the volume and severity of illness and a 3-part categorization (normal volume, high volume, intensive use) to measure stress in the {ED} environment. This retrospective, cross-sectional study collected data from hospital clinical and financial records of all patients seen in 2001 at an urban academic hospital ED. Results Multiple logistic regression models identified factors associated with high volume and intensive use. Factors associated with intensive days included being in a motor vehicle crash; having a gun or stab wound; arriving during the months of January, April, May, or August; and arriving during the days of Monday, Tuesday, or Wednesday. Factors associated with high-volume days included falling from 0 to 10 ft; being in a motor vehicle crash; arriving during the months of January, April, May, or August; and arriving during the days of Monday, Tuesday, or Wednesday. Conclusion These findings offer inputs for reallocating resources and altering staffing models to more efficiently provide high-quality {ED} services and prevent overcrowding.

This paper develops a step-by-step methodology for the application of Full Bayes (FB) approach for before-and-after analysis of road safety countermeasures. As part of this methodology, it studies the posterior prediction capability of Bayesian approaches and their use in crash reduction factor (CRF) estimation. A collection of candidate models are developed to investigate the impacts of different countermeasures on road safety when limited data are available. The candidate models include traditional, random effects, non-hierarchical and hierarchical Poisson-Gamma and Poisson-Lognormal (P-LN) distributions. The use of random effects and hierarchical model structures allows treatment of the data in a time-series cross-section panel, and deal with the spatial and temporal effects in the data. Next, the proposed {FB} estimation methodology is applied to urban roads in New Jersey to investigate the impacts of different treatment measures on the safety of “urban collectors and arterial roads” with speed limits less than 45 mph. The treatment types include (1) increase in lane width, (2) installation of median barriers, (3) vertical and horizontal improvements in the road alignment; and (4) installation of guide rails. The safety performance functions developed via different model structures show that random effects hierarchical P-LN models with informative hyper-priors perform better compared with other model structures for each treatment type. The individual {CRF} values are also found to be consistent across the road sections, with all showing a decrease in crash rates after the specific treatment except guide rail installation treatment. The highest decrease in the crash rate is observed after the improvement in vertical and horizontal alignment followed by increase in lane width and installation of median barriers. Overall statistical analyses of the results obtained from different candidate models show that when limited data are available, P-LN model structure combined with higher levels of hierarchy and informative priors may reduce the biases in model parameters resulting in more robust estimates.

Keywords: Bayesian methods

Study objective This study compares the effect of a brief motivational intervention for alcohol plus a booster given to emergency department (ED) patients with subcritical injuries from a motor vehicle crash with the effect of brief motivational intervention for alcohol plus a booster in patients treated for non-motor vehicle crash-related injuries. Methods A randomized controlled trial (n=539) was conducted at an urban Level I trauma center of brief intervention (1 {ED} session of brief intervention), brief motivational intervention for alcohol plus a booster (1 {ED} session plus booster session), or standard care for injured {ED} patients with an alcohol use problem who were being discharged home. At 12 months, alcohol-related negative consequences and injuries were measured. We performed a secondary analysis comparing motor vehicle crash–injured patients and non–motor vehicle crash–injured patients in the study sample. Results Subcritically injured {ED} patients with harmful or hazardous alcohol use who received brief motivational intervention for alcohol plus a booster had fewer alcohol-related negative consequences and alcohol-related injuries than those receiving brief intervention or standard care at 12-month follow-up (previously reported). A secondary analysis of this result showed that motor vehicle crash patients (n=133) given brief motivational intervention for alcohol plus a booster (n=34) had fewer alcohol-related injuries than those receiving standard care (n=46; P=.001). Moreover, there were no significant differences in alcohol-related injuries among the non–motor vehicle crash–injured patients who received brief intervention or standard care. Conclusion Brief motivational intervention for alcohol plus a booster is a useful intervention for subcritically injured {ED} patients with harmful or hazardous alcohol use. Its effects may be moderated by the cause of injury.

Abstract This paper summarizes the result of a study regarding the creation of tools that can be used in intervention methods in the planning and management of urban road networks in Portugal. The first tool relates the creation of a geocoded database of road accidents occurred in Lisbon between 2004 and 2007, which allowed the definition of digital maps, with the possibility of a wide range of consultations and crossing of information. The second tool concerns the development of models to estimate the frequency of accidents on urban networks, according to different desegregations: road element (intersections and segments); type of accident (accidents with and without pedestrians); and inclusion of explanatory variables related to the road environment. Several methods were used to assess the goodness of fit of the developed models, allowing more robust conclusions. This work aims to contribute to the scientific knowledge of accidents phenomenon in Portugal, with detailed and accurate information on the factors affecting its occurrence. This allows to explicitly include safety aspects in planning and road management tasks.

Keywords: GIS

To better elucidate the incidence, characteristics, and consequences of transport-related injuries in a less developed country in Africa, we undertook an epidemiologic survey in Ghana. A total of 21 105 persons were surveyed, in both an urban area (Kumasi, n=11 663) and a rural area (Brong-Ahafo, n=9442). In the preceding year, a total of 656 injuries were reported in the urban area and 928 injuries reported in the rural area. Transport-related mechanisms accounted for 16% of all injuries in the urban and 10% of all injuries in the rural area. The annual incidence of transport-related injuries was almost identical in the two settings, 997/100 000 persons in the urban area and 941/100 000 in the rural area. In both settings, transport-related injuries were more severe than other types of injuries in terms of mortality, length of disability, and economic consequences. In the urban area, the most common transport-related mechanisms were either to passengers involved in crashes of mini-buses or taxis (29%) or to pedestrians struck by these vehicles (21%). In the rural area, the most common transport-related mechanisms were bicycle crashes. The second most common rural mechanisms were motor vehicle crashes, which were the most severe and which involved commercial (83%) rather than private vehicles. Prevention strategies need to be different from those in developed countries and should target commercial drivers more than private road users.

Keywords: Injury

Abstract The proactive operational strategy in the transport system which is a parallel concept associated with the Intelligent Transportation System (ITS) seems to be modern and right direction of development. However, the basis for its operation is the “information” in the broad sense of the term, on the functioning of the transport system itself. As new technologies develop, there emerge new opportunities of putting to use a wide array of sensors which can deliver more complete traffic data but using complex matrix of sensors is often unjustified economically and confusing. The paper proposes use of magnetometers as an interesting alternative to pass the requirements of simplicity of application, minimum costs and maximum of acquired information. The process of obtaining the information requires analysis of the quantitative and qualitative changes of the magnetic field. The conducted analyses demonstrate the possibility of using the passive magnetic methods for the purpose of monitoring of vehicles. Placement of the magnetic sensor bear out an important issue and was also discussed. During the experimental research it has been proven that passive magnetic methods enable obtaining the information on the movement of a vehicle as well as on the vehicle itself. Estimations of such values as: vehicle’s moving direction, velocity, dimensions, clearance or mass having ferromagnetic properties and even the state of strain in a vehicle’s structure were confirmed in practice. In addition thanks to magneto-mechanical effects the theoretical possibility of assessing the stress occurring in the components of vehicles, which could be indicative of the volume of cargo carried. Moreover, the crash experiment showed the possibility of a collision detection using magnetic signal. The need for obtaining information increases from year to year, with information becoming the biggest asset which enables both development and effective use of the transport system. Included researches, proofs emerging opportunity of more extensive use of magnetic sensors and the passive magnetic methods which could be applied in the modern transportation system.

Keywords: Magnetic signature

Road traffic injuries (RTI) are a public health threat and a major source of disability in developing countries. A population-based analysis of {RTIs} in a testimonially high-risk area of Dar es Salaam, the largest city in the East African country of Tanzania, was carried out with the goal of establishing an {RTI} incidence and to identify {RTI} characteristics that may be used for a targeted injury prevention program in these communities. Geographic cluster sampling was completed in 2 adjacent wards of Dar es Salaam with household surveys administered in person to determine a denominator. Any household members involved in an {RTI} within the previous 12 months received an in-depth questionnaire. Demographics, incident characteristics, medical attention, injuries and disability days were noted. These are described and compared to injury severity and age specific tendencies. Within the 30 clusters, 6001 individuals were interviewed. Of them, 196 were involved in non-fatal {RTIs} within the previous 12 months, resulting in a non-fatal incidence rate of 32.7 {RTIs} per 1000 person years. There were 4 deaths noted. Injuries resulting in a fracture correlated with a disability of more than 30 days. Children were injured as pedestrians 93% of the time and were more likely to be injured on small, unpaved side streets than adults. Most {RTIs} occurred on a highway and affected the lower extremities, required treatment at a hospital, and resulted in a police report being filed 50.2% of the time. In conclusion, {RTIs} in this urban East African setting are a major source of disability. This study provides incidence data and crash characteristics that may be used to construct prevention programs and could validate secondary data sources.

Keywords: Road traffic injuries

Abstract Collector roads are designed to provide a balance between traffic safety, mobility, and land access; however, the literature on the effects of collector lane width on safety is generally inconsistent. This study determines the safety implications of oversized collectors by analyzing collisions statistics, traffic-survey data, and roadway-inventory data from the City of Edmonton. The paper adopts a cross-sectional evaluation methodology by developing negative binomial (NB) safety performance functions (SPFs) for total collisions. Based on the {NB} SPFs, it was found that segment length, traffic volume, access-point density and midblock change was statistically significant and positively related to collisions, while the width was negatively related to collisions and statistically significant. The interaction term of volume and lane width was found to be positively related to collisions. This suggests that the collision rate for oversized collector roads is higher than that for standard-sized roads. It was also found that both standard-sized and oversized roads, with some form of midblock roadway width change, were less safe than those with uniform width. Converting oversized roads to standard size was found to improve safety only for the roads with an average daily traffic (ADT) volume higher than 4000. The maximum crash reduction was estimated to be as high as 28.9%. This study is timely given the contradicting evidence that exists in current literature regarding the relationship between safety and oversized collector roads. For the present data set, this paper provides guidelines on when to convert oversized collector roads to standard-sized collector roads, to improve safety.

Keywords: Cross-sectional evaluation

On a global scale, motorcyclists are typically over-represented in crash statistics. This trend is increasing as although total road crashes and fatalities have decreased over the last fifteen years, motorcycle crash volumes have not. This paper describes the potential of stability control systems to help save motorcyclists’ lives. It summarizes safety research conducted and commissioned by the Federal Highway Research Institute (Bundesanstalt für Straßenwesen, BASt) during the last twenty-five years, with particular focus on the authors’ own work in the last five years, and the state of the art in motorcycle control systems. The conclusion is that further investigation and improvement of these systems should be encouraged. Unfortunately, active stabilization of motorcycles is not presently possible and may not be possible in the future. Therefore, further development, evolution and optimization of Anti-Lock Brake Systems (ABSs) and Traction Control Systems (TCS) should be undertaken, and Anti-Lock Brake Systems (ABSs) should be mandatory on powered two-wheelers. These steps will make the powered two-wheeler a safer urban transportation system.

Keywords: Motorcycle

Abstract The objective of this paper is to test the effectiveness and adaptability of speed reduction markings (SRMs) in downhill sections on urban roads with distinct roadway grades. Empirical data including vehicle speed and acceleration were collected in a driving simulator. Subjective questionnaires were conducted, and two indexes – the relative speed difference and standard deviation of acceleration – were developed to evaluate the effectiveness and adaptability of SRMs. Meanwhile, the effectiveness of driving simulator related to different road alignments and types of {SRMs} has been validated through a field test. Results of subjective questionnaires showed that the majority of subjects had no feelings of nervousness, but they were affected by {SRMs} while driving through downhill sections in all four scenarios (i.e., downhill sections with vertical grades of 3, 2, 1.5 and 1%). In terms of vehicle speed and acceleration, the results of the analysis of variance (ANOVA) and the contrast analysis (S–N–K method) indicated that {SRMs} were significantly effective when roadway grades of downgrade sections were 1.5, 2 and 3%, while transverse speed reduction markings (TSRMs) had significantly worse adaptability (P < 0.05). Therefore, this research recommends that {TSRMs} could be placed in downhill sections with roadway grades of 1.5 or 2%; longitudinal speed reduction markings (LSRMs) could be placed in downhill sections with a roadway grade of 3%. Whether {SRMs} are placed in downhill sections with a roadway grade of 1% would depend on other factors such as financial issues and crash records, which are not considered in this paper.

Keywords: Speed reduction markings

Statistical modeling of traffic crashes has been of interest to researchers for decades. Over the most recent decade many crash models have accounted for extra-variation in crash counts—variation over and above that accounted for by the Poisson density. The extra-variation – or dispersion – is theorized to capture unaccounted for variation in crashes across sites. The majority of studies have assumed fixed dispersion parameters in over-dispersed crash models—tantamount to assuming that unaccounted for variation is proportional to the expected crash count. Miaou and Lord [Miaou, S.P., Lord, D., 2003. Modeling traffic crash-flow relationships for intersections: dispersion parameter, functional form, and Bayes versus empirical Bayes methods. Transport. Res. Rec. 1840, 31–40] challenged the fixed dispersion parameter assumption, and examined various dispersion parameter relationships when modeling urban signalized intersection accidents in Toronto. They suggested that further work is needed to determine the appropriateness of the findings for rural as well as other intersection types, to corroborate their findings, and to explore alternative dispersion functions. This study builds upon the work of Miaou and Lord, with exploration of additional dispersion functions, the use of an independent data set, and presents an opportunity to corroborate their findings. Data from Georgia are used in this study. A Bayesian modeling approach with non-informative priors is adopted, using sampling-based estimation via Markov Chain Monte Carlo (MCMC) and the Gibbs sampler. A total of eight model specifications were developed; four of them employed traffic flows as explanatory factors in mean structure while the remainder of them included geometric factors in addition to major and minor road traffic flows. The models were compared and contrasted using the significance of coefficients, standard deviance, chi-square goodness-of-fit, and deviance information criteria (DIC) statistics. The findings indicate that the modeling of the dispersion parameter, which essentially explains the extra-variance structure, depends greatly on how the mean structure is modeled. In the presence of a well-defined mean function, the extra-variance structure generally becomes insignificant, i.e. the variance structure is a simple function of the mean. It appears that extra-variation is a function of covariates when the mean structure (expected crash count) is poorly specified and suffers from omitted variables. In contrast, when sufficient explanatory variables are used to model the mean (expected crash count), extra-Poisson variation is not significantly related to these variables. If these results are generalizable, they suggest that model specification may be improved by testing extra-variation functions for significance. They also suggest that known influences of expected crash counts are likely to be different than factors that might help to explain unaccounted for variation in crashes across sites.

Keywords: Over-dispersion

Introduction Motorised three-wheeled vehicles (motorised rickshaw) are popular in Asian countries including India. This study aims to describe the crash characteristics and injury patterns for motorised rickshaw occupants and the road users hit-by-motorised rickshaw in urban India. Methods Consecutive cases of road traffic crashes involving motorised rickshaw, irrespective of injury severity, whether alive or dead, presenting to the emergency departments of two large government hospitals and three branches of a private hospital in Hyderabad city were recruited. Crash characteristics, details of injuries, injury severity parameters and outcome were documented in detailed interviews. Results A total of 139 (18%) of the 781 participants recruited were injured as a motorised rickshaw occupant (11%) or were hit by a motorised rickshaw (7%) in 114 crashes involving motorised rickshaw. Amongst motorised rickshaw occupants, single-vehicle collisions (54%) were more frequent than multi-vehicle collisions (46%), with overturning of motorised rickshaw in 73% of the single-vehicle collisions. Mortality (12%), the mean Injury Severity Score (5.8) and rate of multiple injured (60%) indicated a substantial trauma load. No significant differences in injury pattern were found between motorised rickshaw occupants and hit-by-motorised rickshaw subjects, with the pattern being similar to that of the pedestrians and two-wheeled vehicle users. With bivariate analysis for motorised rickshaw occupants, the risk of fatal outcome (odds ratio (OR) 2.60, 95% confidence interval (CI): 0.64–10.54), upper limb injury (OR 2.25, 95% CI: 0.94–5.37) and multiple injuries (OR 2.03, 95% {CI} 0.85–4.83) was high, although not statistically significant in multi-motorised-vehicle collisions as compared with the single-vehicle collisions or overturning. The risk of having multiple injuries (OR 4.55, 95% CI: 1.15–17.95) was significantly higher in motorised rickshaw occupants involved in front collisions. Being a front-seat motorised rickshaw passenger in a vehicle collision increased the risk of having a fatal outcome (OR 7.37, 95% CI: 0.83–65.66) and a Glasgow coma score ≤ 12 (OR 2.21, 95% CI: 0.49–9.89), although not significantly when compared to the back-seat passengers. Conclusion These findings can assist with planning to deal with the consequences and prevention of road traffic injuries due to crashes involving motorised rickshaw, given the high use of these and substantial morbidity of related injuries in India. The need for improved understanding of the risk characteristics of motorised rickshaw is highlighted.

Keywords: Auto

According to accident statistics for Taiwan, the two most common traffic accident locations in urban areas are roadway segments and intersections. On roadway segments, most collisions are due to drivers not noticing the status of leading vehicle. At intersections, most collisions are due to the other driver failing to obey traffic signs. Using a driving simulator equipped with a collision warning system, this study investigated driving performance at different accident locations and between different alarm contents, and identified the relationship between crash occurrences and driving performance. Thirty participants, aged 20–29 years, were recruited in this study. Driving performance measures were perception-reaction time, movement-reaction time, speed and a crash. Experimental results indicated that due to different demands for processing information under different traffic conditions, driving performance differed at the two traffic accident locations. On a roadway segment, perception-reaction time for a beep was shorter than the time for a speech message. Nevertheless, at an intersection, a speech message was a great help to drivers and, thus, perception-reaction time was effectively reduced. In addition, logistic regression analysis indicates that perception-movement time had the greatest influence on crash occurrence.

Keywords: Traffic accident location

Abstract This paper presents a heterogeneity-in-means, random-parameter negative binomial (HMRPNB) model of interchange type effects on interchange and non-interchange segment crash frequencies. For non-interchange segments, upstream and downstream type combinations were evaluated. Eight interchange types, namely, directional, semidirectional, clover, partclover, diamond, part diamond, single-point-urban-interchange (SPUI), and other were studied on the Washington State interstate system. A total of 575 interchange and 578 non-interchange segments were analyzed for the period 1999–2007. In interchange segments, semidirectional, partclover and other (excluding directional, diamond, SPUI, or fullclover) types significantly contributed to heterogeneity in the random parameter effects of average daily traffic, median continuous lighting proportion, minimum and maximum vertical gradients. Full and partial diamond types contributed to heterogeneity in the random parameter effects of median continuous lighting proportion, maximum horizontal degree of curvature, minimum and maximum vertical gradients. In non-interchange segments, the upstream type set including directional, semidirectional, and clover/collector-distributor type, and downstream set of directional, semidirectional, diamond, partclover, partdiamond and other type significantly contributed to heterogeneity in the random parameter means of total length of adjacent interchanges, two foot left shoulder width and two foot right shoulder width proportions. Statistically significant fixed parametric effects included urban/rural location, right continuous lighting proportion, proportion by length of three lane cross section, four lane cross section, three-to-four foot left shoulder, five-to-nine foot left shoulder, ten foot left shoulder, three-to-four foot right shoulder, five-to-nine foot right shoulder, and ten foot right shoulder, as well as number of horizontal curves in segment, and shortest horizontal curve length.

Keywords: Heterogeneity-in-means

Abstract Fatigue/sleepiness is recognised as an important contributory factor in fatal and serious injury road traffic incidents (RTIs), however, identifying fatigue/sleepiness as a causal factor remains an uncertain science. Within Australia attending police officers at a {RTI} report the causal factors; one option is fatigue/sleepiness. In some Australian jurisdictions police incident databases are subject to post hoc analysis using a proxy definition for fatigue/sleepiness. This secondary analysis identifies further {RTIs} caused by fatigue/sleepiness not initially identified by attending officers. The current study investigates the efficacy of such proxy definitions for attributing fatigue/sleepiness as a {RTI} causal factor. Over 1600 Australian drivers were surveyed regarding their experience and involvement in fatigue/sleep-related {RTIs} and near-misses during the past five years. Driving while fatigued/sleepy had been experienced by the majority of participants (66.0% of participants). Fatigue/sleep-related near misses were reported by 19.1% of participants, with 2.4% being involved in a fatigue/sleep-related RTI. Examination of the characteristics for the most recent event (either a near miss or crash) found that the largest proportion of incidents (28.0%) occurred when commuting to or from work, followed by social activities (25.1%), holiday travel (19.8%), or for work purposes (10.1%). The fatigue/sleep related {RTI} and near-miss experience of a representative sample of Australian drivers does not reflect the proxy definitions used for fatigue/sleepiness identification. In particular those {RTIs} that occur in urban areas and at slow speeds may not be identified. While important to have a strategy for identifying fatigue/sleepiness related {RTIs} proxy measures appear best suited to identifying specific subsets of such RTIs.

Keywords: Driver behaviour

Previous research on motorcycle crashes has shown the frequency and severity of accidents in which a non-priority road user failed to give way to an approaching motorcyclist without seeing him/her, even though the road user had looked in the approaching motorcycle's direction and the motorcycle was visible. These accidents are usually called “looked-but-failed-to-see” (LBFS) accidents. This article deals with the effects that the motorcyclist's speed has in these accidents. It is based on the in-depth study and precise kinematic reconstruction of 44 accident cases involving a motorcyclist and another road user, all occurring in intersections. The results show that, in urban environments, the initial speeds of motorcyclists involved in “looked-but-failed-to-see” accidents are significantly higher than in other accidents at intersections. In rural environments, the difference in speed between {LBFS} accidents and other accidents is not significant, but further investigations would be necessary to draw any conclusions. These results suggest that speed management, through road design or by other means, could contribute to preventing “looked-but-failed-to-see” motorcycle accidents, at least in urban environments.

Keywords: Motorcycle crash

Transportation planning models are typically used to estimate future traffic patterns, peak period traffic, travel time, and various environmental or other related traffic flow characteristics. Unfortunately, traffic safety is seldom, if ever, explicitly considered proactively during the transportation planning process. This omission is attributed to various factors, including the lack of available tools needed to estimate the number of crashes during this process. To help fill this void, the research on which this paper is based aimed, as a primary objective, to develop a tool that would allow the estimation of crashes on digital or coded urban transportation networks during the planning process. The secondary objective of the research was to describe how the predictive models should be applied on these networks and explain the important issues and limitations surrounding their application. To accomplish these objectives, safety performance functions specifically created for this work were applied to two sample digital networks created with the help of EMME/2, a software package widely used in transportation planning. The results showed that it is possible to predict crashes on digital transportation networks, but confirmed the reality that the accuracy of the predictions is directly related to the precision of the traffic flow estimates. The crash predictions are also sensitive to how the digital network is coded, and it is shown how appropriate adjustments can be made.

Keywords: Safety

Abstract Traffic congestion in modern cities is an increasing problem having significant consequences in our daily lives. This work proposes a non-intrusive, passive monitoring framework based on the acoustic modality which can be used either autonomously or as a part of a multimodal system and provide valuable information to an intelligent transportation system. We consider a large number of audio classes which are typically encountered in urban areas. We introduce a combination of a powerful audio representation mechanism based on time, frequency and wavelet domain features with universal background modeling which leads to higher recognition accuracies and detection rates (in terms of false alarm and miss probability rates) with respect to commonly employed methodologies. The basic advantage of a class-specific model derived using the universal background modeling logic is its tolerance to data which belong to other sound classes. Another important feature of the proposed system is its ability to detect crash incidents, which apart from their catastrophic impact on human life and property, have negative consequences on the traffic flow. Our experiments are based on the concurrent usage of professional sound effect collections which include audio recordings of high quality. We thoroughly examine the performance of the proposed system on isolated sound events as well as continuous audio streams using confusion matrices and detection error trade-off curves.

Keywords: Acoustic signal processing

Previous research suggests that compared to mobile phone use, eating and drinking while driving is more common and is seen as lower risk by drivers. Nevertheless, snacking at the wheel can affect vehicle control to a similar extent as using a hands-free phone, and is actually a causal factor in more crashes. So far, though, there has not been a controlled empirical study of this problem. In an effort to fill this gap in the literature, we used the Brunel University Driving Simulator to test participants on a typical urban scenario. At designated points on the drive, which coincided with instructions to eat or drink, a critical incident was simulated by programming a pedestrian to walk in front of the car. Whilst the driving performance variables measured were relatively unaffected by eating and drinking, perceived driver workload was significantly higher and there were more crashes in the critical incident when compared to driving normally. Despite some methodological limitations of the study, when taken together with previous research, the evidence suggests that the physical demands of eating and drinking while driving can increase the risk of a crash.

Keywords: Driver distraction

Background Little has been published on changes in young driver fatality rates over time. This paper examines differences in Australian young driver fatality rates over the last decade, examining important risk factors including place of residence and socioeconomic status (SES). Methods Young driver (17–25 years) police-recorded passenger vehicle crashes were extracted from New South Wales State records from 1997–2007. Rurality of residence and {SES} were classified into three levels based on drivers’ residential postcode: urban, regional, or rural; and high, moderate, or low {SES} areas. Geographic and {SES} disparities in trends of fatality rates were examined by the generalized linear model. Chi-square trend test was used to examine the distributions of posted speed limits, drinking driving, fatigue, seatbelt use, vehicle age, night-time driving, and the time from crash to death across rurality and socioeconomic status. Results Young driver fatality rate significantly decreased 5% per year (p < 0.05); however, stratified analyses (by rurality and by SES) showed that only the reduction among urban drivers was significant (average 5% decrease per year, p < 0.01). The higher relative risk of fatality for rural versus urban drivers, and for drivers of low versus high {SES} remained unchanged over the last decade. High posted speed limits, fatigue, drink driving and seatbelt non-use were significantly associated with rural fatalities, whereas high posted speed limit, fatigue, and driving an older vehicle were significantly related to low {SES} fatality. Conclusion The constant geographic and {SES} disparities in young driver fatality rates highlight safety inequities for those living in rural areas and those of low SES. Better targeted interventions are needed, including attention to behavioral risk factors and vehicle age.

Keywords: Young driver

Motor vehicle crashes killed almost 5,000 pedestrians in 2005 in the United States. Pedestrian risk may be higher in areas characterized by urban sprawl. From 2000 to 2004, pedestrian fatality rates declined in the United States, but the Atlanta metropolitan statistical area did not experience the same decline. Pedestrian fatality rates for males, Hispanics, and the 15–34 and 35–54 year age groups were higher in Atlanta than in the United States overall. Pedestrian safety interventions should be targeted to high-risk populations and localized pedestrian settings.

Keywords: Motor vehicle injury

AbstractIntroduction Traffic-related injuries are a major cause of premature death in developing countries. Saudi Arabia has struggled with high rates of traffic-related deaths for decades, yet little is known about health outcomes of motor vehicle victims seeking medical care. This study aims to develop and validate a model to predict in-hospital death among patients admitted to a large-urban trauma centre in Saudi Arabia for treatment following traffic-related crashes. Methods The analysis used data from King Abdulaziz Medical City (KAMC) in Riyadh, Saudi Arabia. During the study period 2001–2010, 5325 patients met the inclusion criteria of being injured in traffic crashes and seen in the Emergency Department (ED) and/or admitted to the hospital. Backward stepwise logistic regression, with in-hospital death as the outcome, was performed. Variables with p < 0.05 were included in the final model. The Bayesian Information Criterion (BIC) was employed to identify the most parsimonious model. Model discrimination was evaluated by the C-statistic and calibration by the Hosmer–Lemeshow Goodness of Fit statistic. Bootstrapping was used to assess overestimation of model performance and obtain a corrected C-statistic. Results 457 (8.5%) patients died at some time during their treatment in the {ED} or hospital. Older age, the Triage-Revised Trauma Scale (T-RTS), and Injury Severity Score were independent risk factors for in-hospital death: T-RTS was best modelled with linear and quadratic terms to capture a flattening of the relationship to death in the more severe range. The model showed excellent discrimination (C-statistic = 0.96) and calibration (H–L statistic 4.29 [p > 0.05]). Internal bootstrap validation gave similar results (C-statistic = 0.96). Conclusions The proposed model can predict in-hospital death accurately. It can facilitate the triage process among injured patients, and identify unexpected deaths in order to address potential pitfalls in the care process. Conversely, by identifying high-risk patients, strategies can be developed to improve trauma care for these patients and reduce case-fatality. This is the first study to develop and validate a model to predict traffic-related mortality in a developing country. Future studies from developing countries can use this study as a reference for case fatality achievable for different risk profiles at a well-equipped trauma centre.

Keywords: Motor vehicle

In this paper, we present evidence of strong relationships between traffic flow conditions and the likelihood of traffic accidents (crashes), by type of crash. Traffic flow variables are measured using standard monitoring devices such as single inductive loop detectors. The key traffic flow elements that affect safety are found to be mean volume and median speed, and temporal variations in volume and speed, where variations need to be distinguished by freeway lane. We demonstrate how these relationships can form the basis for a tool that monitors the real-time safety level of traffic flow on an urban freeway. Such a safety performance monitoring tool can also be used in cost-benefit evaluations of projects aimed at mitigating congestion, by comparing the levels of safety of traffic flows patterns before and after project implementation.

Keywords: Traffic safety

National- and state-level guidance documents conclusively state that fixed lighting improves intersection safety. The sentiment is consistent with other design and safety manuals and is supported by a series of consistent safety findings; however, most published lighting-safety research is focused on rural, stop-controlled intersections and is limited by several methodological issues. The relationship between safety and intersection lighting at rural, signalized and urban locations is not as well documented. Methodological advancements in highway safety analysis justify new estimations of the safety effects of intersection lighting. This paper describes a proposed framework to estimate the safety effects of fixed lighting at a variety of intersection types and locations. Several key issues are explored including availability of relevant crash, lighting, and roadway inventory data; relevant data element structures; proposed analysis taxonomies to assess lighting-safety effects within and across different intersection classifications; specification and estimation of models to estimate expected crash frequencies during day and night; techniques to interpret model parameters, including variable elasticity; and tests of model transferability across states. A sample framework execution using Minnesota intersection data is provided. Results indicate a much lower overall safety benefit from lighting than published studies, but are consistent with estimates included in Highway Safety Manual research.

Keywords: Night-to-day crash ratios

To document the prevalence of alcohol or drug use among elderly drivers admitted to a Level 1 trauma center after motor vehicle crashes, charts from 180 drivers age 60 years or older who were admitted to an urban Level 1 trauma center after motor vehicle crashes were retrospectively reviewed. Overall, 14% of the patients had a positive blood alcohol screen; among men, 21% had a positive screen. Only 55% of the patients were discharged to home. Only one patient (<1%) had a toxicology screen positive for another drug of abuse. Alcohol/drug abuse counselling was offered to only one patient. These results suggest a relatively high prevalence of alcohol use in elderly drivers involved in motor vehicle crashes, particularly men. However, abuse of other drugs was uncommon. Physicians treating intoxicated drivers should consider referral for alcohol counselling.

Keywords: Alcohol

Three-wheeled scooter taxis (TSTs) are being used in many Asian countries and along with buses are the main mode of public transport for the urban middle class population. The {TST} chassis is made by the manufacturer and the body is fabricated by local body-makers. The vehicle is not subject to any crash safety specifications.This work is the first attempt to study the crash characteristics of {TSTs} using a crash simulation computer software (MADYMO) with the objective of developing practical guidelines to make the vehicle safer in collisions with other motorized road users and pedestrians. Impact modelling was done for the standard and modified {TST} occupied by a driver and one passenger at impact velocities of 10–30 km/h crashing with a pedestrian and a bus front.The results show that the passenger and the driver of the standard {TST} can sustain high HICs, face/head contact forces and tibia/knee contact forces in crashes with buses at velocities 20 km/h and greater. The magnitude of these parameters can be reduced slightly by small changes in the design of the interior and padding of critical surfaces. To increase the safety of the {TST} significantly major modifications need to be incorporated in the design of {TSTs} and bus fronts. Pedestrian impact simulations indicate that it may be possible to reduce the impact forces by changing the shape of the front of the TST.The results indicate that it should be possible to improve the crash safety properties of vehicles indigenously designed in Asian and African countries by the use of crash simulation models like MADYMO. This procedure is relatively inexpensive and can provide the first approximations for design of safer vehicles.

Keywords: Impact

Abstract Study objective: A cohort of 4,729 junior college students in Taiwan was studied to determine risk factors for increased severity of motorcycle injuries. Methods: Crash characteristics were collected by using self-administered questionnaires soon after a student was involved in a motorcycle crash. The proportional odds model with generalized estimating equations, with correlated ordinal responses for collisions categorized into not injured, mildly injured, and severely injured categories, was used to determine the odds of injury severity. Results: A total of 1,889 motorcycle crashes involving 1,284 persons occurred over a 20-month period from November 1994 to June 1996. There were 1,339 noninjuries, 474 mild injuries, and 76 severe injuries. The adjusted odds ratio (OR) of rural to urban roads having a greater level of injury severity was 1.64. Compared with noncollisions, collisions with a moving car (adjusted OR=1.76), a parked car (adjusted {OR} 1.90), or another stationary object (adjusted OR=2.31) increased the odds for a greater level of injury severity. Riders using Sanyang (adjusted OR=1.63) and Yamaha (adjusted OR=1.39) motorcycles had greater odds of being involved in a crash with a greater level of injury compared with those riding Kymco motorcycles. Darkness (adjusted OR=1.65) and greater speeds (adjusted OR=1.63 to 4.69) also increased the odds of greater injury severity. Conclusion: At the time of motorcycle crashes, factors such as being on rural roads, collisions with a heavier object, some motorcycle makes, darkness, and greater speeds increased the severity of motorcycle injuries among these young adult riders. [Ann Emerg Med. 2003;41:783-791.]

A number of epidemiological studies have reported drivers who use a mobile phone while driving have an elevated risk of being involved in a crash. This is particularly concerning as a survey of drivers in the Spanish region of Catalunya found that approximately 87% own mobile phones. The present study investigated the reported frequency of mobile phone use on Spanish roads (for talking and using SMS), the characteristics of the drivers who use mobile phones while driving and whether they altered their driving behaviour when using a mobile phone. The research found that more than 60% use a mobile phone while driving and that the phone is mostly used for making calls, rather than using SMS. In general, males and females use mobile phones about the same reported frequency, although males were more likely to use a mobile phone to talk on the highway. The pattern for age was the same for both male and female participants, with the younger drivers using {SMS} more frequently than older drivers. On urban roads almost half of the drivers reported changing their driving behaviour when using a mobile phone, while on the highway this figure was slightly over 41%. The reported frequency of using a mobile phone to talk on urban roads was significantly correlated with crash involvement. However, this affect disappeared once the contributions of the demographic and descriptive variables had been partialled out.

Keywords: Mobile phones

A disaggregate spatial analysis, using enumeration district data for London was conducted with the aim of examining how congestion may affect traffic safety. It has been hypothesized that while congested traffic conditions may increase the number of vehicle crashes and interactions, their severity is normally lower than crashes under uncongested free flowing conditions. This is primarily due to the slower speeds of vehicles when congestion is present. Our analysis uses negative binomial count models to examine whether factors affecting casualties (fatalities, serious injuries and slight injuries) differed during congested time periods as opposed to uncongested time periods. We also controlled for congestion spatially using a number of proxy variables and estimated pedestrian casualty models since a large proportion of London casualties are pedestrians. Results are not conclusive. Our results suggest that road infrastructure effects may interact with congestion levels such that in London any spatial differences are largely mitigated. Some small differences are seen between the models for congested versus uncongested time periods, but no conclusive trends can be found. Our results lead us to suspect that congestion as a mitigator of crash severity is less likely to occur in urban conditions, but may still be a factor on higher speed roads and motorways.

Keywords: Traffic safety

Average annual conviction rates (1990–2000) of people arrested for driving under the influence of alcohol in each of New Mexico's 33 counties are described. Conviction rates vary from 58 to 95%. Rates are correlated with political conservatism, being higher where a higher proportion of voters voted for the republican presidential candidates, and with measures of crowding in the courts. Conviction rates are higher in rural than urban areas and are correlated with a low prevalence of alcohol-related problems in the population. The variance in conviction rates is higher in rural than urban areas, and higher where measures of court crowding are low. The results suggest that political culture and the efficiency of court functioning are each independently associated with conviction rates for {DWI} and may also be associated in a reciprocal fashion with both low {DWI} arrest rates and alcohol-involved crash rates.

Keywords: Traffic accidents

A substantial proportion of urban motor-vehicle crashes occur at intersections, and many intersection crashes involve drivers running through red lights. The present study used data collected by an automated camera, trained observers, and department of motor vehicle records to provide a profile of red light runners at an urban intersection. It compares characteristics of these drivers and their vehicles with those of a comparison group of drivers that had an opportunity to run the red light but did not. Red light runners, as a group, were younger, less likely to wear seat belts, had poorer driving records, and drove smaller and older vehicles than the drivers who did not run red lights. Research has shown that red light running can be reduced through automated enforcement using red light cameras and by environmental modifications, such as changing traffic signal timing.

Purpose As the population ages, trauma in the elderly is an increasingly recognized source of elderly morbidity. However, previous reviews on the topic provide only broad recommendations. The purpose of this study was to examine the elderly recidivist cohort at an urban trauma center for mechanisms of repeat injury. Methods The trauma registry at a major urban trauma center was queried to identify all patients aged 65 and older admitted from 1991–2010. Recidivist admissions were compared to nonrecidivist admissions. Demographics, mechanism of injury, injury location, length of stay, and mortality data were collected. Recidivists’ mechanism of injury was compared with their initial mechanism of injury. Descriptive statistics, Student t-test, and a z-rank test of proportions were applied with significance set to P ≤ 0.05. Results Between 1991 and 2010, 6476 patients aged 65+ were admitted, of which 79 (1.22%) were recidivists. Of these, 64 patients were aged 65 and older for both admissions. Most often, recidivists were male (70% versus 60%) and injured in penetrating trauma (17% versus 7.5%, P = 0.045). Recidivists trended towards more frequent injuries in bicycle collisions (3% versus 1.9%) and all-terrain vehicle (ATV)/motorcycle crashes (6.3% versus 1.7%), but were less likely to be hit by cars (49% versus 36%, P = 0.034). At least two thirds of recidivist patients injured in falls, ATV/motorcycle accidents, and stabbings had previously been injured by the same mechanism. Conclusions The overall recidivism rate in the elderly population is low. Nevertheless, recidivists were more susceptible to penetrating trauma, ATV/motorcycle collisions, and possibly bicycle accidents. These findings can help design counseling initiatives and injury prevention programs that target specific elderly trauma patients.

Keywords: Elderly

Intersection crashes are a major traffic problem. Greater knowledge of causation is required in order to prevent them with the implementation of active safety measures. Causation charts were aggregated to establish whether common patterns of interlinked factors could be found. The data used comprised causation charts for 52 drivers involved in 26 in-depth investigated urban intersection crashes. The charts were compiled by means of the Driving Reliability and Error Analysis Method (DREAM) version 2.1, in which contributing factors are systematically analysed, classified and linked in a causation chart. The charts were aggregated for six defined risk situations, four for drivers without the right of way and two for those with the right of way. In two risk situations, one for drivers with and one for the drivers without the right of way, common patterns showed that the drivers had not seen the other vehicle due to distractions and/or sight obstructions. A frequently occurring pattern for the drivers with the right of way was that they had not expected another vehicle to cross their path. The absence of clear patterns in three risk situations for the drivers without the right of way was due to the low number of charts and rather unique circumstances. Parts of the aggregated charts showed an unwarranted variation, identified as a consequence of inconsistent charts. The present study shows that the rather unique approach of aggregating causation charts has potential, provided that the charts are consistent.

Keywords: Collision avoidance

In order to identify and describe a pattern in bus and coach incident related injuries and fatalities, and to suggest possible future measures for improvement of bus and coach safety, a literature analysis was performed. The results formed a multi-faceted pattern, which briefly can be described as follows; women travelled more frequently by bus as compared to men. Injuries sustained predominantly affected women 60 years of age and older. Of all traffic fatalities in Europe, bus and coach fatalities represented 0.3–0.5%. In the {OECD} countries, the risk of being killed or seriously injured was found to be seven to nine times lower for bus and coach occupants as compared to those of car occupants. Despite the fact that fatalities were more frequent on rural roads, a vast majority of all bus and coach casualties occurred on urban roads and in dry weather conditions. Boarding and alighting caused about one-third of all injury cases. Collisions were a major injury-contributing factor. Buses and coaches most frequently collided with cars, but unprotected road users were hit in about one-third of all cases of a collision, the point of impact on the bus or the coach being typically frontal or side. Rollovers occurred in almost all cases of severe coach crashes. In this type of crash projection, total ejection, partial ejection, intrusion and smoke inhalation were the main injury mechanisms and among those, ejection being the most dangerous. A 2-point belt may prevent passenger ejection, but in frontal crashes when the upper abdominal parts and the head hit the seatback in front, it could, however, contribute to head and thoracic injuries. Hence, a 3-point belt provides the best restraint in rollovers and frontal crashes.

Keywords: Bus

Research has shown that using a mobile phone whilst driving may increase the risk of being crash involved by as much as nine times. As around 65% of New Zealand's population own mobile phones, this represents a potentially very significant hazard. In order to effectively target interventions towards those drivers who use mobile phones while driving, information is needed about the characteristics of these drivers. The present study investigated the frequency of mobile phone use on New Zealand's roads and the characteristics of drivers who use mobile phones while driving. The research found that more than half (57.3%) of the participants used a mobile phone at least occasionally while driving. Those who reported using a mobile phone more often whilst driving tended to; be male, reside in a main urban area, report a higher annual mileage, drive a later model car with a larger engine, prefer a higher driving speed, have less driving experience (in years) and to be younger. In line with previous research, there was also a significant relationship between crash involvement and use of a mobile phone whilst driving. However, once the contributions of the demographic and descriptive variables had been partialled out, using hierarchical logistic regression, the relationship between crash involvement and mobile phone use was no longer significant.

Keywords: Mobile phones

The {UK} Intelligent Speed Adaptation (ISA) project produced a rich database with high-resolution data on driver behaviour covering a comprehensive range of road environment. The field trials provided vital information on driver behaviour in the presence of ISA. The purpose of this paper is to exploit the information gathered in the field trials to predict the impacts of various forms of {ISA} and to assess whether {ISA} is viable in terms of benefit-to-cost ratio. {ISA} is predicted to save up to 33% of accidents on urban roads, and to reduce {CO2} emissions by up to 5.8% on 70 mph roads. In order to investigate the long-term impacts of ISA, two hypothetical deployment scenarios were envisaged covering a 60-year appraisal period. The results indicate that {ISA} could deliver a very healthy benefit-to-cost ratio, ranging from 3.4 to 7.4, depending on the deployment scenarios. Under both deployment scenarios, {ISA} has recovered its implementation costs in less than 15 years. It can be concluded that implementation of {ISA} is clearly justified from a social cost and benefit perspective. Of the two deployment scenarios, the Market Driven one is substantially outperformed by the Authority Driven one. The benefits of {ISA} on fuel saving and emission reduction are real but not substantial, in comparison with the benefits on accident reduction; up to 98% of benefits are attributable to accident savings. Indeed, {ISA} is predicted to lead to a savings of 30% in fatal crashes and 25% in serious crashes over the 60-year period modelled.

Keywords: Intelligent Speed Adaptation

Abstract This paper presents a modeling effort for developing safety performance models (SPM) for urban intersections for three major Brazilian cities. The proposed methodology for calibrating {SPM} has been divided into the following steps: defining the safety study objective, choosing predictive variables and sample size, data acquisition, defining model expression and model parameters and model evaluation. Among the predictive variables explored in the calibration phase were exposure variables (AADT), number of lanes, number of approaches and central median status. {SPMs} were obtained for three cities: Fortaleza, Belo Horizonte and Brasília. The {SPM} developed for signalized intersections in Fortaleza and Belo Horizonte had the same structure and the most significant independent variables, which were {AADT} entering the intersection and number of lanes, and in addition, the coefficient of the best models were in the same range of values. For Brasília, because of the sample size, the signalized and unsignalized intersections were grouped, and the {AADT} was split in minor and major approaches, which were the most significant variables. This paper also evaluated {SPM} transferability to other jurisdiction. The {SPM} for signalized intersections from Fortaleza and Belo Horizonte have been recalibrated (in terms of the Cx) to the city of Porto Alegre. The models were adjusted following the Highway Safety Manual (HSM) calibration procedure and yielded Cx of 0.65 and 2.06 for Fortaleza and Belo Horizonte {SPM} respectively. This paper showed the experience and future challenges toward the initiatives on development of {SPMs} in Brazil, that can serve as a guide for other countries that are in the same stage in this subject.

Keywords: Safety performance models

Abstract Introduction: Denmark is one of the leading cycling nations, where cycling trips constitute a large share of the total trips, and cycling safety assumes a top priority position in the agenda of policy makers. The current study sheds light on the aggravating and mitigating factors associated with cyclist injury severity on Danish roads by examining a comprehensive set of accidents involving a cyclist and a collision partner between 2007 and 2011. Method: This study estimates a generalized ordered logit model of the severity of cyclist injuries because of its ability to accommodate the ordered-response nature of severity while relaxing the proportional odds assumption. Results: Model estimates show that cyclist fragility (children under 10 years old and elderly cyclists over 60 years of age) and cyclist intoxication are aggravating individual factors, while helmet use is a mitigating factor. Speed limits above 70–80 km/h, slippery road surface, and location of the crash on road sections are aggravating infrastructure factors, while the availability of cycling paths and dense urban development are mitigating factors. Heavy vehicle involvement and conflicts between cyclists going straight or turning left and other vehicles going straight are aggravating vehicle involvement factors. Practical applications: The results are discussed in the context of applied policies, engineering, and traffic management solutions for bicycle safety in Denmark.

Keywords: Cycling accidents

This paper reports the results of a study that explored the relationship between fatal crashes and conflict rates at mid-block on 14 locations in Delhi, India. All locations had a mix of motorized and nonmotorized traffic. The sites were selected to represent low, medium and high fatality rates. The analysis was done in two stages. The first stage used recent 3-year statistics along the entire street. The second stage focused on each fatal crash for mid-block segments on those streets. Peak-hour traffic at 14 selected locations was videotaped. Trained observers recorded traffic compositions at mid-block, average space mean speeds by mode and conflicts by type, reactor mode and cause mode. After converting raw conflict counts to rates, site ranking went from high to low conflict rate sites. The studies showed a weak crash-conflict association. Conflict data for various sites were compared for different combinations of conflicts. The comparison revealed that the presence of only a few non-motorized modes is enough to cause conflicts between motorized vehicles and on-road non-motorized vehicles. The study did not provide a conclusive relationship between mid-block conflicts and fatal crash sites. However, the conflict study provided useful insights into the interaction between different traffic entities in the traffic streams of 14 sites. An important conclusion of this study is that a traffic-planning emphasis on studying conflict rates may not result in reducing fatality rates on urban roads along mid-block segments.

Keywords: Conflict

The circumstances of a rural and urban sample of fatalities in vehicles less than six years old is described. The data originate from an in-depth, multidisciplinary study of accidents conducted in England since 1983. The sample is biased towards collisions that result in occupant injury, and this paper will concentrate on those accidents in which an occupant has been fatally injured. The initial police reporting of the fatalities included 11% of the deaths occurring from natural causes. Of the crash-related deaths with complete data, some 43% were frontal and lateral impacts, and they are analysed in greater detail. Thirty-six percent of restrained occupants died in lateral collisions. In both frontal and lateral crashes, large amounts of intrusion result in direct loading of the head and chest, particularly. Under-run crashes with large trucks constitute 30% of frontal death cases, and only 12% of fatalities received fatal injuries from belt loads. Of those cases, additional loading by unrestrained rear passengers could have been an important feature. Multiplicity of severe injuries is the rule for restrained fatalities, with head injuries as the most common cause of death. Eighty-two percent died within an hour of their crashes. Some consequences for vehicle compatibility in crashes are discussed.

Older pedestrians have been shown to be over-involved in casualty crashes, compared to younger pedestrians, in recent reports. This study set out to investigate whether older pedestrians' road crossing behaviour might render them more vulnerable to crashes because of declines in their physical, sensory, perceptual or cognitive abilities. An initial ‘blackspot’ accident analysis highlighted the types of crashes in which older (and younger) adult pedestrians were involved and likely crossing actions. Road crossing behaviour was then systematically measured from unobtrusive video recordings of individual road crossings for a sample of younger and older pedestrians at several urban locations. On two-way undivided roads, older pedestrians crossed more frequently when there was closer moving traffic and generally adopted less safe road crossing strategies than their younger counterparts. On one-way divided roads, their crossing behaviour was considerably more safe and similar to that of younger pedestrians. The findings suggest that age-related perceptual and cognitive deficits may play a substantial role in many of the crashes involving older pedestrians.

Keywords: Accidents

Study Objectives: We compare the population-based death rates from traffic crashes in the Hispanic and non-Hispanic white populations in a single state, and compare fatally injured Hispanic and non-Hispanic drivers with respect to safety belt use, alcohol involvement, speeding, vehicle age, valid licensure, and urban-rural location. Methods: Hispanic and non-Hispanic white motorists killed in traffic crashes in 1991-1995 were studied (n=2,272). Data from death certificates (age, sex, education, race, and ethnicity) and the Fatality Analysis Reporting System (FARS; driver, vehicle, and crash information) were merged. Average annual age-adjusted fatality rates were calculated; to compare Hispanic and non-Hispanic white motorists, rate ratios (RR) and 95% confidence intervals (CIs) were calculated. Odds ratios (ORs), adjusted for age, sex, and rural locale, were calculated to measure the association between Hispanic ethnicity and driver and crash characteristics. Results: Eighty-five percent of {FARS} records were matched to death certificates. Compared with non-Hispanic white motorists, Hispanics had higher crash-related fatality rates overall (RR 1.75, 95% {CI} 1.60 to 1.92) and for drivers only (RR 1.62, 95% {CI} 1.41 to 1.85). After adjustment for age, sex, and rural locale, Hispanic drivers had higher rates of safety belt nonuse (OR 1.81, 95% {CI} 1.20 to 2.72), legal alcohol intoxication (OR 2.73, 95% {CI} 1.97 to 3.79), speeding (OR 1.36, 95% {CI} 0.99 to 1.88), and invalid licensure (OR 2.58, 95% {CI} 1.78 to 3.75). The average vehicle age for Hispanic drivers (10.1 years, 95% {CI} 9.3 to 11.0) was greater than for non-Hispanic white motorists (8.8 years, 95% {CI} 8.4 to 9.2). Conclusion: Compared with non-Hispanic whites, Hispanic drivers have higher rates of safety belt nonuse, speeding, invalid licensure and alcohol involvement, with correspondingly higher rates of death in traffic crashes. As traffic safety emerges as a public health priority in Hispanic communities, these data may help in developing appropriate and culturally sensitive interventions. [Harper JS, Marine WM, Garrett CJ, Lezotte D, Lowenstein SR. Motor vehicle crash fatalities: a comparison of Hispanic and non-Hispanic motorists in Colorado. Ann Emerg Med. December 2000;36:589-596.]

Data on road traffic fatalities, serious casualties and slight casualties in each local authority district England and Wales were obtained for 1995–2000. District-level data were assembled for a large number of potential explanatory variables relating to population numbers and characteristics, traffic exposure, road length, curvature and junction density, land use, elevation and hilliness, and climate. Multilevel negative binomial regression models were used to identify combinations of risk factors that predicted variations in mortality and morbidity. Statistically significant explanatory variables were the expected number of casualties derived from the size and age structure of the resident population, road length and traffic counts in the district, the percentage of roads classed as minor, average cars per capita, material deprivation, the percentage of roads through urban areas and the average curvature of roads. This study demonstrates that a geographical approach to road traffic crash analysis can identify contextual associations that conventional studies of individual road sections would miss.

Keywords: Road traffic accidents

SummaryObjective To determine whether the classical trimodal distribution of trauma deaths is still applicable in a contemporary urban New Zealand trauma system. Methods All trauma deaths in the greater Auckland region between 1 January 2004 and 31 December 2004 were identified and reviewed. Data was obtained from hospital trauma registries, coroner autopsy reports and police reports. Results There were 186 trauma deaths. The median age was 28.5 years and the median Injury Severity Score was 25. The predominant mechanisms of injury were hanging (36%), motor vehicle crashes (31.7%), falls (9.7%), pedestrian–vehicle injury (5.4%), stabbing (4.3%), motorcycle crashes (3.2%), and pedestrian–train injury (2.2%). Most deaths were from central nervous system injury (71.5%), haemorrhage (15.6%), and airway/ventilation compromise (3.8%). Multi-organ failure accounted for 1.6% of deaths. Most deaths occurred in the pre-hospital setting (80.6%) with a gradual decrease thereafter. Conclusion There was a skew towards early deaths. The trimodal distribution of trauma deaths was not demonstrated in this group of patients.

Keywords: Wounds and injuries

Seat belt use on Spain’s highways is more than 80%, while on the urban roads this figure is around 50%. As there was little information available to explain the difference in seat belt use rates, the main aim of this study was to investigate why there is a lower rate of seat belt use on urban roads. A number of perceptions, beliefs and expectancies about seat belt use were examined to identify variables that discriminated between seat belt users and non-users on urban roads. The subjects were 398 undergraduate students (aged 17–47) studying at the University of Girona, Spain. On the urban roads reported discomfort from using the seat belt was higher, while perceptions of risk (for non-users), safety perceptions (for those using a seat belt), beliefs about the seriousness of a crash or the effectiveness of the seat belt were all lower than on the highway. Perceptions of safety, discomfort, and social influence predicted seat belt use on urban roads. Concern about being fined for not using a seat belt did not predict seat belt use. The results of this research suggest that in order to increase seat belt use on urban roads, the issue of discomfort must be addressed. In addition, prevention campaigns should include information about the effectiveness of the seat belt in preventing/reducing injuries or deaths on urban roads. The results also highlight the importance of social influence for determining seat belt use/non-use and the potential role social influence could play in increasing seat belt usage.

Keywords: Seat belt

ResumenObjetivos Valorar el efecto de las circunstancias ambientales sobre el riesgo de muerte de los conductores de vehículos de dos ruedas de motor (VDRM) tras un accidente de tráfico. Métodos Se ha estudiado la serie de casos formada por los 309.626 conductores de {VDRM} implicados en accidentes de tráfico con víctimas en España, entre 1993 y 2002, recogidos por la Dirección General de Tráfico. La variable dependiente ha sido la defunción del conductor. Como variables ambientales se han considerado factores temporales (año, mes, día y hora) y espaciales (zona del accidente, iluminación, entre otros). También se han recogido potenciales factores de confusión dependientes del conductor (edad, sexo, uso de casco), del vehículo y el tipo de accidente. Se han obtenido, mediante modelos de regresión de Poisson, riesgos relativos crudos y ajustados para cada categoría ambiental. Resultados Para la mayoría de las variables temporales, no hay asociación con el riesgo de defunción en el análisis ajustado, a excepción de un mayor riesgo para la conducción de madrugada. El riesgo aumenta fuertemente en carretera (especialmente autopistas y autovías) con respecto a las zonas urbanas, para las que hay una clara relación dosis-respuesta entre un menor tamaño del municipio y una mayor letalidad. Conclusiones Tras ajustar por los factores de riesgo dependientes del conductor, el efecto de los factores ambientales sobre el riesgo de muerte del conductor de un {VDRM} tras el accidente se circunscribe a la zona donde se produce el accidente y, en menor medida, a la hora en que ocurre. Objectives To assess the effect of environmental factors on the risk of death for drivers of two-wheeled motorized vehicles (TWMV) after a crash. Methods We studied a case series comprising all 309,626 drivers of {TWMV} involved in road crashes with victims compiled by the Spanish Department of Transportation from 1993 to 2002. The dependent variable was death of the driver. Environmental factors included temporal variables (year, month, day and hour of the crash) and spatial variables (area where the accident took place and light conditions, among others). Confounding variables related to the driver (age, sex, helmet use), the vehicle, and the type of crash were also recorded. Poisson regression models were constructed to obtain crude and adjusted relative risks for each environmental condition. Results In the adjusted analysis, no association was found between most time-related factors and the risk of death, with the exception of an increased risk in the early hours of the morning. The risk of death was much greater for crashes on open roads (especially highways and motorways) than in urban areas, where the risk of death increased as the size of the town decreased. Conclusions After adjustment for several confounders, the only environmental factors related to the risk of death in {TWMV} drivers after a crash were the area when the crash occurred, and (more weakly) the time of day when it occurred.

Keywords: Accidentes de tránsito

This study evaluates the expected benefits of using the {ALINEA} ramp metering algorithm as a method for real-time safety improvement on an urban freeway. The objective of this research is to use ramp metering to produce a significant decrease in the risk of crashes on the freeway while avoiding any significant adverse effects on operation. This is achieved by simulating the freeway during the congested period in micro-simulation and testing various ramp metering configurations to determine which provides the best results. Statistical measures developed for the same stretch of freeway using loop detector data are used to quantify the risk of crashes as well as the benefits in each of the alternative strategies. The study concludes that there are significant benefits in metering multiple ramps when the feedback ramp metering algorithm is implemented at multiple locations. It was found that increasing the number of metered on-ramps produces increasing safety benefits. Also, a shorter cycle length for each of the meters and a higher critical occupancy value leads to better results.

Keywords: Crash risk

Background With new data available, we sought to update existing literature on the prevalence of self-reported seat belt use by state, region, and rural/urban status and to estimate the strength of the association between seat belt use and rural/urban status adjusted for type of seat belt law and several other factors. Methods We examined data on self-reported use of seat belts from 50 states, the District of Columbia, and three territories using the 2008 Behavioral Risk Factor Surveillance System, a state-based random-digit-dialed telephone survey (n = 406,552). Reported seat belt use was assessed by state, U.S. Census regions, and U.S. Department of Agriculture (USDA) rural/urban continuum codes. Results Overall, 85% of adults in the United States reported they always used seat belts. Regionally, the West had the highest prevalence of persons who reported that they always wear seat belts (89.6%) and the Midwest had the lowest (80.4%). States with primary seat belt laws had the highest prevalence of reported seat belt use, compared with states with secondary or no laws. After adjusting for various sociodemographic characteristics, body mass index, and type of seat belt law, persons in the most densely populated metropolitan areas were significantly more likely to report always wearing seat belts than those in most sparsely populated rural areas (adjusted odds ratio = 2.9). Conclusion Our findings reinforce the evidence that primary enforcement seat belt laws are effective for increasing seat belt use, and suggest that upgrading to primary enforcement laws will be an important strategy for reducing crash-related fatalities in rural areas.

Keywords: Seat belt use

Objective To establish the associations between pedestrian injury and explanatory variables such as vehicular characteristics, temporal trends, and road environment. Methods A retrospective analysis of de-identified pedestrian crash data between 2002 and 2006 was conducted using the Building & Road Research Institute's crash data bank. We estimated the odds ratios associated with casualty fatalities using a multinomial logistic regression. Results There were 812 pedestrian casualties reported, out of which 33% were fatal, 45% sustained serious injuries requiring hospitalization, and 22% were slightly injured but were not hospitalized. Crossing the roadway accounted for over 70% of all pedestrians’ deaths. Whereas fatalities in 2002 and 2003 were statistically indistinguishable from those of 2004 (p > 0.05), in comparison with 2004, there were significantly fewer fatalities in 2005 and 2006 (78% and 65% reduction respectively). According to police report, the probability that a pedestrian fatality occurring in Ghana attributable to excessive speeding is 65%. The adjusted odds ratio of pedestrian fatality associated with speeding compared with driver inattentiveness was 3.6 (95% CI: 2.5–5.2). It was also observed that generally, lighter vehicular masses were associated with lower pedestrian fatalities. Compared with buses, pedestrians were less likely to die when struck by private cars (52%), pick-up trucks (57%), and motorcycles (86%). Conclusion Pedestrian death remains the leading cause of fatality among urban road users in Ghana. Risk factors associated with pedestrian fatality include being hit by heavy vehicles, speeding, and roadside activities such as street hawking, jaywalking and nighttime walking. Steps which may contribute to reducing pedestrian fatalities include measures to reduce vehicles speeds in settlements, providing traffic medians and lighting streets in settlements, and discouraging street and roadside activities such as hawking.

Keywords: Pedestrians

Traffic incidents are the primary cause of delay in urban settings, reducing capacity and creating risks for both motorists and incident response personnel. As incident duration increases, the risk of secondary incidents or crashes also becomes a problem. In response to these issues, many communities have initiated incident management programs aimed at detecting, responding to, and clearing incidents in order to restore freeways to full capacity as quickly and safely as possible. This study involved the development of fully parametric hazard duration models to examine those factors impacting the time required by the Michigan Department of Transportation's Freeway Courtesy Patrol to clear incidents that occurred on the freeway network in metropolitan Detroit. These models were developed using traffic flow data, roadway geometry information, and an extensive incident database. Four fully parametric hazard duration models are developed, each assuming a different underlying probability distribution for the hazard function. In general, each modeling framework provided similar results, though a log- logistic distribution is shown to provide a better fit for the incident clearance data in comparison to other distributions. Various factors were found to significantly affect incident clearance time, including the time of day and time of year at which the incident occurred, the geometric and traffic characteristics of the freeway segment, and the characteristics of the incident.

Keywords: freeway

The story of the redevelopment of the Isle of Dogs in London's Docklands is one that has only partially been told. Most professional and academic interest in the area ceased following the property crash of the early 1990s, when the demise of Olympia & York, developers of Canary Wharf, seemed to bear out many contemporary critiques. Yet the market bounced back, and so did Canary Wharf, with increasingly profound impacts on the rest of the Island. This paper takes an explicitly historical approach using contemporaneous professional critiques and more reflective academic accounts of the planning and development of the Isle of Dogs to examine whether we can now conclude that an urban renaissance has taken place in this part of London. An extensive review of the literature is supplemented with analysis of physical change on the ground and by analysis of the range of relevant plans and policy documents that have been produced to guide development over the 35-year period since the regeneration began. The paper asks: What forms of planning have we seen on the Island; what role has design played in these; what outcomes have resulted from these processes; and, as a result, have we yet seen an urban renaissance?

Keywords: Isle of Dogs

This research investigated the types of situations that cause drivers to become angry while driving. The Driver Anger Scale [Deffenbacher, J. L., Oetting, E. R., & Lynch, R. S. (1994). Development of a driver anger scale. Psychological Reports, 74, 83–91] was used to investigate driver anger amongst 861 drivers. The resultant data were factor analysed, producing four categories of anger provoking situations; progress impeded, risky driving, hostile gestures and discourteous driving. Overall levels of driver anger were higher than equivalent research in the UK, but appeared to be lower than that found in America. In line with overseas research, female drivers reported more anger overall and in two of the four categories of driver anger (risky driving and hostile gestures). There were also regional differences, with the drivers from the main urban areas reporting more anger than those from the secondary urban areas. Reported anger declined with age for all categories of anger provoking situations. Those drivers reporting a higher level of driving anger across all potential anger inducing situations tended to be; female, younger, from a main urban area, report a higher annual mileage, be less experienced (in terms of years driving) and prefer a higher speed. The overall level of driver anger was not related to crash involvement, and neither were any of the four categories of driver anger.

Keywords: Driver anger

AbstractObjective Road traffic injuries pose a significant threat to the Egyptian population. Recent estimates revealed that Egypt experiences 42 road traffic deaths per 100,000 population (1.8% of all deaths in the country), which is the highest death rate in the region. More than half of the road traffic crashes that resulted in injuries occurred on the country's highways. Despite the significance of this public health problem, very little risk factor information currently exists. The overall goal of this paper is to understand the burden of speeding and the level of seatbelt and child restraint use on a highway (Cairo Ring Road) and two urban roads crossing Alexandria city (Kornish and Gamal Abd-Elnaser roads). Methods Two rounds of seatbelt and child restraint observational studies and one round of speed observational study were carried out between 2011 and 2012. Results Findings revealed that seatbelt use among drivers and front seat passengers were low for all three sites (range: 11.1% to 19.8% for drivers; 2.9% to 4.0% for front seat passengers). Similarly, child restraint use in cars with children was very low ranging from 1.1% to 3.9% on all three roads. All three roads experienced a high percentage of vehicles driving above the speed limit (39.4% on Kornish Road, 22.6% on Cairo Ring Road, 11.8% on Gamal Abd Elnaser Road), with the majority of these vehicles driving 1 to 10 kilometer above the speed limit. Conclusion Future interventions need to focus on enhancing enforcement of speed and seatbelt wearing, closing gaps in legislation, and standardizing existing data systems to help inform good road safety policies.

Keywords: Road safety

Environmental psychologists suggest that appropriately landscaped roadside scenes may have a reducing influence on travel-related stress or may improve attention, yet there is very little data available that establishes the nature of the relationship between roadside landscaping and driver safety. Traditional transportation researchers suggest that aesthetic enhancements are a problematic component of the roadside landscape because of the severity of vehicle/tree collisions and a perception that roadside aesthetics can distract the driver causing safety risk. Costly planning processes arise as members of the local communities debate with public utility and transportation management staff on the subject of appropriate roadside landscaping. To test the effect of landscape improvements on driver performance, this study used a comparison of before-and-after crashes as a quantitative measure of roadside greening. Researchers examined 61 road sections in Texas that were landscape designed as either urban arterials or state highways. The hypothesis tested was to determine whether landscape-improved sections of the roadway were safer compared to the same road section before landscape improvements at 10 sites were very well controlled as study sites. The findings of this study show a significant decrease in crash rate after landscape improvements were implemented at the 95% confidence level on 10 urban arterial or highway sites in Texas. The contribution of this study is to further investigate the effect that landscape features are having on driver behavior which appear to be associated with positive changes in safety result from design. However, these findings need further research to verify a relationship between driver's visual perception according to travelway corridor landscape treatments.

Keywords: Roadside landscape

Introduction Previous work using data from the 1980s showed higher rates of pedestrian mortality in the southern United States. Methods This study was a descriptive analysis of state-specific mortality information from the National Center for Health Statistics for 1999–2002 and the National Highway Traffic Safety Administration for 2003. Results Highest rates were in the southern rim (“Sunbelt”) states for the U.S. population and for the non-Hispanic white population. Rural rates in the highest quartile were 2.1 (95% {CI} 1.8 to 2.6) times those in the lowest quartile. Urban rates in the highest quartile were 2.2 (95% {CI} 1.9 to 2.5) times those in the lowest quartile. Posted speed limits at crash sites were 2.6 (95% {CI} 2.0 to 3.4) times more likely to be ≥ 35 mph (48.3 km/h) in the highest quartile than in the lowest quartile. Pedestrians killed in the highest quartile were 1.9 (95% {CI} 1.2 to 3.1) times more likely to have blood alcohol concentrations ≥ 0.25 g/dL than pedestrians in the lowest quartile. Conclusions The highest pedestrian fatality rates concentrate in Sunbelt states experiencing rapid population growth in the past 50 years. This pattern may result from at least three features of these states: (a) a high percentage of urban vehicle miles traveled; (b) urban sprawl; and (c) a high prevalence of alcohol use — especially heavy use — among Sunbelt pedestrians.

Keywords: Unintentional injury

In recent years, there has been a renewed interest in applying statistical ranking criteria to identify sites on a road network, which potentially present high traffic crash risks or are over-represented in certain type of crashes, for further engineering evaluation and safety improvement. This requires that good estimates of ranks of crash risks be obtained at individual intersections or road segments, or some analysis zones. The nature of this site ranking problem in roadway safety is related to two well-established statistical problems known as the small area (or domain) estimation problem and the disease mapping problem. The former arises in the context of providing estimates using sample survey data for a small geographical area or a small socio-demographic group in a large area, while the latter stems from estimating rare disease incidences for typically small geographical areas. The statistical problem is such that direct estimates of certain parameters associated with a site (or a group of sites) with adequate precision cannot be produced, due to a small available sample size, the rareness of the event of interest, and/or a small exposed population or sub-population in question. Model based approaches have offered several advantages to these estimation problems, including increased precision by “borrowing strengths” across the various sites based on available auxiliary variables, including their relative locations in space. Within the model based approach, generalized linear mixed models (GLMM) have played key roles in addressing these problems for many years. The objective of the study, on which this paper is based, was to explore some of the issues raised in recent roadway safety studies regarding ranking methodologies in light of the recent statistical development in space–time GLMM. First, general ranking approaches are reviewed, which include naïve or raw crash-risk ranking, scan based ranking, and model based ranking. Through simulations, the limitation of using the naïve approach in ranking is illustrated. Second, following the model based approach, the choice of decision parameters and consideration of treatability are discussed. Third, several statistical ranking criteria that have been used in biomedical, health, and other scientific studies are presented from a Bayesian perspective. Their applications in roadway safety are then demonstrated using two data sets: one for individual urban intersections and one for rural two-lane roads at the county level. As part of the demonstration, it is shown how multivariate spatial {GLMM} can be used to model traffic crashes of several injury severity types simultaneously and how the model can be used within a Bayesian framework to rank sites by crash cost per vehicle-mile traveled (instead of by crash frequency rate). Finally, the significant impact of spatial effects on the overall model goodness-of-fit and site ranking performances are discussed for the two data sets examined. The paper is concluded with a discussion on possible directions in which the study can be extended.

Keywords: Roadway safety

Background Cervical collar brace protection of the cervical spine at the scene of the incident is the first priority for emergency medical technicians treating patients who have sustained trauma. However, there is still controversy between over- or underprotection. The objective of this study was to survey the cervical spine injury of lightweight motorcycle accident victims and further evaluate the neck collar protection policy. Materials and Methods We retrospectively reviewed patients who sustained lightweight motorcycle injuries, assumed to have been at a low velocity, with incidence of cervical spine damage, from a single medical center's trauma registration from 2008 to 2009. Patients were divided into 2 groups: those who were immobilized by cervical collar brace and those who were not. Results Of the 8633 motorcycle crash victims, 63 patients had cervical spine injury. The average of the injury severity score in these patients was 14.31 ± 8.25. There was no significant correlation of cervical spine injury between the patients who had had the neck collar applied and those who had not (χ2, P = .896). The length of stay in intensive care unit was longer in the patients who had the neck collar applied, but the total hospital length of stay was not statistically different to the patients who did not have the neck collar applied. Conclusion The incidence of cervical spinal injuries in the urban area lightweight motorcyclists is very low. Prehospital protocol for application of a cervical collar brace to people who have sustained a lightweight motorcycle accident in the urban area should be revised to avoid unnecessary restraint and possible complications.

In most developed countries, information on road crashes are routinely collected by the police. However, comparison of police records and hospital data underlines a deficit of the number of road accidents in the routine statistics. In La Réunion, a French overseas dependency, an epidemiological study of injuries leading to hospitalisation or deaths has been performed from June 1993 to June 1994. The comparison between hospital data and police records showed that only 37.3% of non-fatally traffic-injured in-patients were recorded by the police. Length of stay in hospital, physician in charge of the first aid, urban place of the crash, type of vehicle involved, day and time of the crash and blood alcohol concentration were significantly associated with the presence in the police file. Police overestimated the severity of the injuries. Police notified 100 deaths on the 115 counted by the study. In France, non-fatally traffic-injured should be followed 30 days to improve quality of police death records. A capture–recapture method was used to estimate the total number of injured people. The capture–recapture method consists in merging information from several sources of notification to determine the real number of cases in the population and the exhaustivity of each source. We estimated that 346 subjects were injured in one month whereas police data recorded only 87 and hospital data 137. This method seems interesting to use in routine after validation when unique personal identifiers are available.

Keywords: Road injuries

Study objective The literature on the costs of treating alcohol-impaired motor vehicle crash victims is largely based on inpatient data. Less is known about the more frequent emergency department (ED) evaluations for those who are discharged home. Our objective is to measure the difference in charges and length of stay between alcohol-impaired and nonimpaired drivers in this population. Methods This was a retrospective study of charts and billing data for all drivers in motor vehicle crashes, aged 21 to 65 years, treated at an urban Level I trauma center in 2005 and discharged home from the ED. Patients were divided into alcohol-positive and -negative groups according to alcohol level, documentation of recent alcohol use, or clinical intoxication. Itemized charges were tabulated and compared across groups. Results Of 1,618 eligible patients, median charges were higher for alcohol-positive patients by 4,538 (95% confidence interval [CI] 2,755 to 5,665). Imaging was 69% of the charge differential because of a higher frequency of imaging (91% versus 70%) and more expensive studies (median difference 2,464; 95% {CI} 1,507 to 3,400) for alcohol-positive patients. Median length of stay was higher for alcohol-positive patients by 3.3 hours (95% {CI} 2.7 to 4.1 hours). When stratified by trauma-protocoled triage destination, median charges were higher for alcohol-positive versus -negative patients in non–critical care beds by 2,229 (95% {CI} 1,039 to 2,693). For patients triaged to critical care beds, the difference in charges was only 132 (95% {CI} –1,677 to 1,233). Conclusion The presence of alcohol substantially increased charges and length of stay for {ED} evaluations of injured drivers discharged home, especially for patients who were triaged to non-critical care beds. The magnitudes are striking for this minimally injured population and represent an underreported burden of alcohol-impaired driving.

Introduction: This study analyzes the in-service performance of roadside hardware on the entire urban State Route system in Washington State by developing multivariate statistical models of injury severity in fixed-object crashes using discrete outcome theory. The objective is to provide deeper insight into significant factors that affect crash severities involving fixed roadside objects, through improved statistical efficiency along with disaggregate and multivariate analysis. Method: The developed models are multivariate nested logit models of injury severity and they are estimated with statistical efficiency using the method of full information maximum likelihood. Results: The results show that leading ends of guardrails and bridge rails, along with large wooden poles (e.g. trees and utility poles) increase the probability of fatal injury. The face of guardrails is associated with a reduction in the probability of evident injury, and concrete barriers are shown to be associated with a higher probability of lower severities. Other variables included driver characteristics, which showed expected results, validating the model. For example, driving over the speed limit and driving under the influence of alcohol increase the probability of fatal accidents. Drivers that do not use seatbelts are associated with an increase in the probability of more severe injuries, even when an airbag is activated. Impact on industry: The presented models show the contribution of guardrail leading ends toward fatal injuries. It is therefore important to use well-designed leading ends and to upgrade badly performing leading ends on guardrails and bridges. The models also indicate the importance of protecting vehicles from crashes with rigid poles and tree stumps, as these are linked with greater severities and fatalities.

Keywords: Injury severity

Study objective: To determine the effect of the use of a motorcycle helmet on reducing the mortality, morbidity, and health care costs resulting from motorcycle crashes. Design: A prospective, multicenter study of all eligible motorcycle crash victims. Setting: The emergency departments of eight medical centers across the state of Illinois, including representatives from urban, rural, teaching, and community facilities. Type of participants: All motorcycle crash victims presenting less than 24 hours after injury for whom helmet information was known. Data were collected from April 1 through October 31, 1988. Measurements and main results: Fifty-eight of 398 patients (14.6%) were helmeted, and 340 (85.4%) were not. The nonhelmeted patients had higher Injury Severity Scores (11.9 vs 7.02), sustained head/neck injuries more frequently (41.7 vs 24.1%), and had lower Glasgow Coma Scores (13.73 vs 14.51). Twenty-five of the 26 fatalities were nonhelmeted patients. By logistic regression, the lack of helmet use was found to be a major risk factor for increased severity of injury. A 23% increase in health care costs was demonstrated for nonhelmeted patients (average charges 7, 208 vs 5, 852). Conclusion: Helmet use may reduce the overall severity of injury and the incidence of head injuries resulting from motorcycle crashes. A trend toward higher health care costs was demonstrated in the nonhelmeted patients.

Keywords: helmet use, motorcycle

Speed cameras can reduce speeding and injury crashes, but in many communities they are confined to low-speed settings such as residential streets and school zones. In 2006 the city of Scottsdale, Arizona, implemented a 9-month pilot program to evaluate the feasibility and effects of highly visible speed camera enforcement on a busy urban freeway. This was the first use of fixed speed cameras on a major {US} highway. Deployment of six cameras along an 8-mile corridor was associated with large declines in mean speeds and an 88% decrease in the odds of vehicles traveling 11 mph or more above the 65 mph limit. Traffic speeds increased soon after the pilot program was suspended. In addition to reducing speeding along the enforcement corridor, speed cameras were associated with large reductions in speeding on the same highway but 25 miles away from the camera installations. However, traffic speeds were fairly stable on urban freeways in Scottsdale that were not part of the study road. Public opinion surveys found widespread concerns about speeding on the Loop 101 freeway and high levels of support for speed camera enforcement on this road.

Keywords: Speed cameras

A survey of drivers carried out in Ontario in 1988 has provided data on time spent driving as well as the distances driven for licensed drivers of both sexes in six age groups and three regions. Substantial differences were found in times, distances, and distance/time ratios among these groups. Men drove 50% greater distances, but spent only 30% more time driving than women; speed, averaged over each day's driving, was lower for older drivers than for younger drivers. Differences in speed reflect differences in the driving done in urban or rural areas, and differences in the opportunity for road crashes; such differences, whether based on units of time or distance, will also affect both the comparisons of accident rates and the perceptions of risk among different groups of drivers. A definition of exposure to risk of road crash is required that considers both time and distance appropriately.

Purpose: To explore rates of pedestrian fatalities in Arizona, and how rates and circumstances of pedestrian deaths differ by race/ethnicity, urban or rural residence, age, and gender. Methods: Using the Fatality Analysis Reporting System and the National Center for Health Statistics’ Multiple Cause of Death file, pedestrian fatalities in Arizona from 1990 through 1996 were classified by gender, race/ethnicity, and urban or rural residence. Age-adjusted rates were calculated and adjusted for the proportion of rural residence. Age analyses compared pedestrian fatality rates in 10-year age groups by race/ethnicity. Conditions associated with pedestrian deaths were examined, including the time and day of occurrence, alcohol involvement, and degree of pedestrian contribution to the crash. Results: American Indians had rates of pedestrian deaths 6 to 13 times those of non-Hispanic whites. Elevated rates for American Indians were found in urban and rural areas, in both genders, in all age groups in men, and in five of nine age groups in women. American-Indian pedestrian death rates and relative risks (RRs) were higher in rural areas than in urban areas. Compared to non-Hispanic whites, urban Hispanic males had an elevated {RR} of 1.56, rural Hispanic females had an {RR} of 2.45, and urban African-American (AA) females had an {RR} of 2.33. However, significantly elevated rates, compared to non-Hispanic whites, were limited to Hispanic males aged <5 years and African-American females aged 65 to 74 years. In all race/ethnic groups, except rural Hispanics, men had higher rates than women, although American-Indian women had higher rates than non-Hispanic whites, African Americans, and Hispanic men. Rural residence accounted for 27% of the excess American-Indian pedestrian mortality. Sixty-one percent of urban, American-Indian pedestrian deaths occurred on weekends, compared to 29% among non-Hispanic whites and 46% among Hispanics. American Indians had six times the rate of alcohol-related pedestrian deaths as non-Hispanic whites in urban areas and 16 times that respective rate in rural areas. Hispanics had an alcohol- involvement {RR} of 1.82 in urban areas, but the {RR} was not elevated in rural areas. When blood alcohol was measured, the blood alcohol concentration was >0.20 g/dL in 64.4% of American Indians, 35% of Hispanics, and 29% of non-Hispanic whites. Conclusion: A major disparity in pedestrian fatalities exists for both American-Indian men and women in urban and rural areas. Other racial/ethnic groups have elevated pedestrian fatality rates that are gender and residence specific, and are limited to specific age groups. Much of the American-Indian excess mortality is alcohol related and associated with residence in rural areas.

Keywords: accidents

By the end of the 1970's, all states in the U.S. had modified their laws to permit drivers to turn right on steady red at signalized intersections. Police-reported crash data from six states where permissive right turn on red (RTOR) laws were adopted during 1974–1977, as well as data from three states where the law in effect was unchanged throughout the period, were used to determine the effect of adopting such laws on the frequency of crashes involving right turning maneuvers at signalized intersections. The increase in the overall frequency of such crashes in states that adopted permissive right turn on red laws exceeded by more than 20% the comparable change in states that retained the same laws. Larger increases were found in urban areas (25%), and for pedestrian crashes (57%) especially in urban areas (79%). An increase of over 30% was found for child pedestrians, 100% for adults, and 110% for elderly pedestrians after adoption of RTOR.

Objective To investigate the prevalence of mobile phone and seat belt use in driving in college students aged 18-24 years. Methods The study consisted of two phases. In the first phase, a questionnaire was given to 265 college students. The sample contained 188 males and 77 females. In the second phase, the data pertaining to road accident injuries from March 20, 2007 to March 20, 2008 were collected from Bahonar Central Hospital in Kerman, Iran, and analyzed. Results There were 14.0% of male and 19.0% of female participants traveled belted while driving on urban roads. It indicated that the participants unbelted or using mobile phone were more involved in accidents in last three years. This study also revealed that 19.0% of male and 4.2% of female drivers considered using mobile phone in driving not hazardous. The highest injury and property damage crash rates were 87 and 137 per 100 000 inhabitants, which occured in male group aged 18–24 years. And 30% of all fatalities were 19–24 years old. Conclusions More than 50% of college students traveled unbelted. The females were less involved in road accident injuries. The college students aged 18-24 years had the highest percentages of trauma and head injury.

Keywords: Craniocerebral trauma

Aims The aims of the present study were to characterize fatal traffic accident victims in a major urban center in Brazil and their association with alcohol consumption. Methods Cross-sectional study of 907 fatal traffic accident victims in Sao Paulo, in 2005. Results Adult males between the ages of 25 and 54 represented the majority of cases with positive blood alcohol concentrations (BAC). Overall, males had a higher proportion of {BAC} and mean {BAC} than females. Pedestrians, particularly those with no detectable BAC, were typically older than other victims. Most accidents (total and BAC-positive) happened on weekends between midnight and 6 a.m. Considering all victims, 39.4% were positive (BAC over 0.1 g/l). When only drivers (automobile, motorcycle and bicycle) were evaluated, 42.3% had {BAC} over the legal limit (0.6 g/l). Conclusions Alcohol is associated with nearly half of all traffic accident deaths in the city of Sao Paulo, especially for days and times associated with parties and bars (weekends between 12 a.m. and 6 a.m.).

Keywords: Traffic accident

In motor vehicle collisions the mechanism of injury is important in determining severity as well as for triage decisions in the pre-hospital phase of patient management. This study correlates deformation of the basic structures of the passenger compartment [windscreen, control panel (dashboard) and steering wheel] with occupants’ injuries in passenger vehicle head-on collisions involving non-airbag-carrying vehicles, with or without compartment intrusion. The study took place in the broad urban area of Patras, over an 18-month period (January 2000–June 2001) and evaluated 48 vehicle crashes. Car and compartment deformation are significant factors affecting occupants’ injuries and consequently the appropriate type of further treatment, either in the hospital setting or primary health-care centres. It would be particularly useful to transmit the post-crash condition of a vehicle to the trauma dispatch centre, utilising satellite technology, thus allowing the centre to organise the rescue teams, plan triage in advance and provide the emergency medical personnel with all necessary information before their arrival at the scene of the accident.

Because of rapid increase in the urban population and hence road traffic, the vehicle–pedestrian crashes are more frequent and have become a major concern in road traffic safety. Though the bumper of a vehicle plays an important role to protect the vehicle body damage in low speed impacts, many bumpers particularly in larger vehicles are too stiff for pedestrian protection and safety. To prevent lower extremity injuries in car–pedestrian collisions, it is important to determine the loadings that car front structures impart on the lower extremities and the mechanisms by which injuries are caused. In the present work, a dynamic legform impactor model is introduced and validated against EEVC/WG17 criteria. The collision mechanism between a {GMT} bumper and the legform impactor model is investigated numerically using LS-DYNA software. The effect of the height of the impact point of bumper assembly to lower extremity injuries is also investigated. In this paper, it is shown that changing the local stiffness of bumper assembly due to the change in the height of the bumper and distribution of stiffness from upper parts of the bumper assembly to lower parts are the most important parameters in the pedestrian’s leg injuries. As lower extremity injuries are related to the lower bumper height, developing special legform impactors for different countries with different average person height seems essential in investigating the effect of people’s height on lower extremity injuries.

Keywords: {EEVC} legform impactor

Young adults with attention deficit hyperactivity disorder (ADHD) are at higher risk for being involved in automobile crashes. Although driving simulators have been used to identify and understand underlying behaviors, prior research has focused largely on single-task, non-distracted driving. However, in-vehicle infotainment and communications systems often vie for a driver's attention, potentially increasing the risk of collision. This paper explores the impact of secondary tasks on individuals with and without ADHD, a medical condition known to affect the regulation of attention. Data are drawn from a validated driving simulation representing periods before, during, and after participation in a secondary cognitive task. A hands-free phone task was employed in a high stimulus, urban setting and a working memory task during low stimulus, highway driving. Drivers with {ADHD} had more difficulty on the telephone task, yet did not show an increased decrement in driving performance greater than control participants. In contrast, participants with {ADHD} showed a larger decline in driving performance than controls during a secondary task in a low demand setting. The results suggest that the interaction of the nature of the driving context and the secondary task has a significant influence on how drivers with {ADHD} allocate attention and, in-turn, on the relative impact on driving performance. Drivers with {ADHD} appear particularly susceptible to distraction during periods of low stimulus driving.

Keywords: Driving simulation

Study objectives: Several studies have suggested that legally intoxicated drivers who are injured when involved in a motor vehicle crash are unlikely to be cited or prosecuted for driving under the influence (DUI). The purpose of this study was to determine (1) the rates of citation and prosecution of legally intoxicated drivers who are injured in a motor vehicle crash and hospitalized in a Level I trauma center, (2) the rates of previous and subsequent alcohol-related citation in this population, and (3) the rate of referral for treatment of alcohol-related problems made during the hospital stay. Methods: In a retrospective review of trauma registry and Cleveland Municipal Court records from January 1993 through April 1995, we examined the records of all drivers injured in a motor vehicle crash who were transported to a Level I urban trauma center, admitted to the trauma service, and determined to have a blood alcohol content (BAC) of .10 gm% or higher at the time of admission to the emergency department. Results: Seventy drivers admitted after a motor vehicle crash had a {BAC} of .10 gm% or higher. This represented 33% of the drivers older than 16 years of age who were admitted to the trauma service. Twenty-three drivers (32.8%) were cited for DUI, and 15 (21%) of the 70 were successfully prosecuted and convicted. Four of 23 cited drivers had previous citations; another 5 incurred subsequent citations during the study period. Eight of the 70 drivers who were admitted with a high {BAC} were referred for outpatient alcohol counseling after discharge. None were offered counseling as inpatients. Conclusion: Citation and prosecution rates of legally intoxicated drivers injured in motor vehicle crashes and hospitalized in our trauma center were low. Recognition of alcoholism and inpatient counseling were rare. Multiple alcohol-related citations were common among drivers cited for DUI. [Cydulka RK, Harmody MR, Barnoski A, Fallon W, Emerman CL: Injured intoxicated drivers: Citation, conviction, referral, and recidivism rates. Ann Emerg Med September 1998;32:349-352.]

Introduction Unrestrained drivers and passengers are involved in a significant amount of fatalities and injuries in motor-vehicle crashes in the United States. While the literature documents the effectiveness of seat belt usage in reducing crash outcomes, such as fatalities and the severity of injuries, there is a need to evaluate the impact of seat belt usage by drivers and passengers in their respective vehicles. These findings could help develop effective education and enforcement strategies to enhance occupant safety. Method This paper summarizes a study comparing seat belt usage rates of drivers and passengers based on whether or not the driver uses a seat belt. Observational data from 50 sites in the state of Nevada over 3 years are used for analyses. The data are stratified based on the gender of the driver and passengers in the front seat of the vehicle and are based on area type (rural or urban). Results A comparison of the rates of seat belt usage across for the aggregated data and for various types of disaggregation and statistical analyses to compare the rates of seat belt use among passengers based on the use of seat belts by drivers confirms that when drivers use seat belts, their respective passengers are much more likely to use seat belts. Further, if drivers do not use seat belts, their passengers are not likely to use seat belts. This observation is comparable for male drivers and female drivers, and also for male passengers and female passengers. Further, there are no differences for combinations of the genders of the drivers and passenger (i.e., both male or female, or one male and one female). Impact on industry These results suggest that education and enforcement strategies would benefit most by working toward increasing seat belt usage rates among drivers.

Keywords: Seat belt use

This study investigated the manner in which the driving performance of young people was affected by a collision warning system when they encountered a driver running a red light at an intersection. Furthermore, the causal relationship among driving performance, traffic factors and intersection accidents was examined using Path Analysis. Participants drove a driving simulator with an intersection collision warning system (ICWS) in a simulated urban area. The driving performance measures recorded were reaction time, speed, lateral position deviation and crash events. Experimental results indicated that drivers who drove a vehicle with an {ICWS} audio signal at an intersection had a shorter reaction time, a lower speed and a reduced accident rate than those observed while driving a vehicle without {ICWS} audio signal. Furthermore, Path Analysis showed that the {ICWS} had an indirect effect on accident rate reduction through improved driving performance. The location of intersection accident had both direct and indirect effects on the accident rate. The number of driving days per week had a direct effect on accident rate reduction.

Keywords: Driving performance

Driver distraction represents a well-documented and growing contribution to the road safety problem. This study used a naturalistic, observational approach to examine if children in vehicles are a significant source of driving distraction. Families with children aged between 1 and 8 years drove an instrumented “study vehicle” on their regular trips for 3 weeks. A discrete video recording system in the vehicle provided images of the driver and front seat passenger, the rear seat child passengers and the traffic ahead. The video-recordings inside and outside the vehicle were analysed to identify potential distracting activities, where ‘distraction’ was broadly defined as any activity that distracted the driver or competed for their attention while driving. In addition, all potentially distracting activities that involved the driver looking away from the forward roadway for more than 2 s while the vehicle was in motion were also coded. Video-recordings were analysed for 92 driving journeys undertaken by 12 families including 25 children and 19 drivers. The mean journey duration was approximately 16 min (range: 2 min–3 h 34 min). Most journeys were undertaken during the day (89%), with the mother driving (65%) and without a front seat passenger (64%). Driving journeys were predominantly undertaken in urban areas (97%), on suburban roads/streets (94%), and under low complexity traffic conditions (91%). Most journeys involved some source of potential driver distraction (98%), with drivers distracted for 18% of the driving journey. The most frequent types of distracting activities that drivers engaged in included: touching their head or their face (35%), interacting with child passengers in the rear seat (12%), and engaging with the front seat passenger (9%). Almost three-quarters of these potentially distracting activities were engaged in by the driver while the study vehicle was in motion (72%) and 14% of all potentially distracting activities involved the driver's eyes off the roadway for greater than 2 s while the vehicle was in motion, thereby potentially doubling their crash risk. The most frequent child-related activities that drivers engaged in included: turning to look at the rear seated occupants or viewing the children using the rear-view mirror (76.4%), engaging in conversation with their children (16%), assisting their children (e.g., passing food and drink [7%]) and playing with their children (1%). Drivers spent significantly longer periods of time engaged in non-child occupant-related activities compared with child occupant-related activities and were significantly more likely to have their eyes off the forward roadway for greater than 2 s while engaged in non-child occupant-related activities (14%) compared to child occupant-related activities (10%). The results suggest that drivers need to be educated about the potential crash and injury risks associated with both child occupant-related and non-child occupant-related activities while driving their vehicle.

Keywords: Child safety

Road crashes are largely attributed to driving violations, a behaviour which is committed willingly. The most commonly used theoretical model to predict this behaviour has been the theory of planned behaviour (TPB) and its predecessor, the theory of reasoned action. This study includes a sample of 275 people of the general public holding a current driving licence. Its general aim is to predict the intention to commit two different driving violations: speeding in an urban area and dangerous overtaking by an expanded version of the {TPB} containing separate measures of descriptive norms and past behaviour. The results show that both past behaviour and descriptive norm make a unique contribution towards the prediction of intention to violate. Furthermore, it also found that the effect of descriptive norms is greater in a situation described as ‘risky’. The effect of age and annual mileage were significant with regard to speeding indicating that young drivers and those who use the car regularly are more likely to speed. Implications of the current findings for the development of intervention programmes are discussed.

Keywords: Attitudes

The aim of this study was to investigate the opinions of female adolescents living in the {ROI} on issues relating to body image and dietary practice. A qualitative study was selected to enable the issues to be explored in depth. Sixteen focus groups were executed with adolescent females (n = 124) aged 15–16 years. Data collection took place during class time in both rural and urban schools in the ROI. Data were analysed using a qualitative thematic methodology, namely framework analysis. High levels of body dissatisfaction existed and dieting was found to be prevalent. The influence of media celebrities was significant. The girls not only aspired to be like them in terms of physique but also followed their alleged dieting regimes in detail. Peers also influenced body dissatisfaction and dieting practices. Consequently, eating habits were altered to accommodate this quest for thinness with a tendency to skip main meals as part of the dieting practice while maintaining an unhealthy snacking pattern. The results are of concern as the adolescent females were utilising unhealthy methods of weight control such as skipping meals and fasting in their quest to obtain a thin physique. A slim body image was deemed important for peer acceptance; hence ‘crash’ dieting was in existence. This mindset and the resultant dietary practices may have negative health consequences during both adolescence and later life. School interventions targeting adolescent females and focusing on healthy eating and body image are therefore urgently required.

Keywords: Dieting

Background/purpose Traumatic spinal injury (TSI) is an uncommon source of morbidity and mortality in children. The aim of this study was to describe childhood {TSI} in a single level 1 urban pediatric trauma center. Methods The authors retrospectively analyzed all children younger than 14 years with TSI, treated at a level I pediatric trauma center between 1991 and 2002 (n = 406, 4% total registry). All children were stratified according to demographics, mechanisms, type and level of injury, radiologic evaluations, associated injuries, and mortality. Results The mean age was 9.48 ± 3.81 years. The most common overall mechanism of injury was motor vehicle crash (MVC; 29%) and ranked highest for infants. Falls ranked highest for ages 2 to 9 years. Sports ranked highest in the 10 to 14 year age group. Paravertebral soft tissue injuries were 68%. The most common injury level was the high cervical spine (O-C4). The incidence of spinal cord injury without radiologic abnormality (SCIWORA) was 6%. Traumatic brain injury (37%) was the most common associated injury. Overall mortality rate was 4% in this urban catchment. Conclusions {TSI} in children requires a different preventive and therapeutic logarithm compared with that of adults. The potential devastating nature of {TSI} warrants that the health care team always maintains a high index of suspicion for injury. Future prospective studies are needed to further elucidate injury patterns.

Keywords: Pediatric trauma

Objective To examine the relationship between the built environment and overweight status in children. Methods Analyses were based on 2482 children aged 5–18 and their primary care givers who participated in the second wave of the Child Development Supplement (CDS-II) of the Panel Study of Income Dynamics (PSID). CDS-II is a nationally representative survey that was administered in October 2002–May 2003. A number of built environment characteristics were examined: population density, alpha index of connectivity, urban design, pedestrian fatality from motor vehicle crashes, restaurant density, and grocery store and convenience store densities. Also, interviewer's observations on neighborhood physical disorder, such as the condition and upkeep of the buildings and street surface on the block were analyzed. Results Living in a neighborhood with higher convenience store density (OR = 1.3, p < 0.05) and living in a neighborhood built after 1969 (OR = 1.9, p < 0.01) is associated with a higher probability of being overweight for children and adolescents. Living in the neighborhood where no physical disorder (OR = 0.5, p < 0.01) is observed is associated with a decreased likelihood of being overweight. Conclusions The results of this study emphasize a particular importance of the built environment of the neighborhood for weight status of children and adolescents.

Keywords: Environment

Several studies have showed that driving under the influence of alcohol and/or certain illicit or medicinal drugs increases the risk of a (severe) crash. Data with respect to the question whether this also leads to a more severe accident are sparse. This study examines the relationship between the use of alcohol, illicit drugs and/or medicinal drugs and the severity of an accident within a group of drivers that were involved in a crash in The Netherlands. Blood samples of 993 drivers, collected in the period from October 1998 through September 1999, were linked to accident characteristics as available from the National Transport Research Centre. The outcome measure was the severity of the accident. An accident was considered severe when the accident had resulted in hospital admission or death. All the blood samples obtained after the accident were screened for the presence of alcohol, illicit drugs (opiates, amphetamines and amphetamine-like substances, cocaine and metabolites, methadone, cannabinoids) and medicinal drugs (benzodiazepines, barbiturates and tricyclic antidepressants). The strength of the associations between exposure to the different classes of alcohol/drugs/medicines and the severity of the accident was evaluated using logistic regression analysis and were expressed as odds ratios (OR), adjusted for age, gender, time of the day, day of the week and urban area. The most frequently detected drugs were cannabinoids, benzodiazepines and cocaine. Our results showed no clear association between the use of alcohol, illicit drug and/or medicinal drug use and the severity of the accident. Given the process of obtaining blood samples from drivers involved in accidents and the retrospective nature of the study, we cannot rule out the occurrence of selection bias. Therefore, our findings need further confirmation.

Keywords: Alcohol

Historically, most of the research conducted on the development of safer, breakaway mailbox supports has been for rural mailbox installations. Consequently, only one full-scale crash test was performed on an urban, neighborhood mailbox installation and was met with unsatisfactory safety performance results. In response to the potential threat to motor vehicle and occupant safety, the Midwest Roadside Safety Facility, in cooperation with the Unites States Postal Service, researched and developed a new breakaway concept for centralized-delivery equipment, such as the Neighborhood Delivery and Collection Box Unit (NDCBU). The new breakaway concept consisted of modifying the existing anchor bolt configuration to include bolts fabricated from a material of higher strength, a lower percent elongation, and a smaller diameter and with a special two-step washer to retrofit existing mailboxes. Nonlinear finite element analysis (FEA) with LS-DYNA was also used to predict the potential for the new breakaway mount and attached mailbox to meet the crash test requirements of {NCHRP} Report No. 350, Recommended Procedures for the Safety Performance Evaluation of Highway Features. Concept evaluation and refinement was made with the use of several static pull tests, dynamic bogie tests, and severe corrosion tests. Results from the {FEA} and laboratory testing showed that the new breakaway base should significantly improve the safety performance of the NDCBU.

Keywords: Roadside safety

Background Underage drinking and driving is a national safety issue. We hypothesized students would have lenient thoughts and behaviors about drinking and driving. The aim of our study was to assess current adolescent behavior and attitudes on alcohol use and driving. Methods A survey of 40 multiple choice questions was administered to 11th and 12th grade students at an urban, public high school in Los Angeles, California. Results Of the 1282 upper class students, 302 completed the survey (127 eleventh graders and 175 twelfth graders; 31% response rate). Overall, 64.2% reported having used alcohol. Significantly more 12th graders than 11th graders had consumed alcohol (71.4% versus 54.3%; P = 0.002); irrespective of gender. Binge drinking was reported by 8.6% of students (11.4% 12th graders vs. 4.7% 11th graders; P = 0.06). Nearly one-half (49.7%) of students indicated they disapproved of binge drinking. Students were more willing to discuss alcohol issues with peers (63.2%) than parents (44.0%) or teachers/counselors (19.5%; P = < 0.001). Most students (88.1%) indicated they would not drive when they had consumed one to two drinks. Conclusions Greater than 60% of respondents reported having used alcohol. Students expressed strong concern about alcohol-impaired driving. Binge drinking appears prevalent in high school-aged individuals and increases with age. The lack of communication between students and adults on the topic of alcohol offers opportunity for improvement. Since the number of young drivers injured in alcohol-related crashes remains unacceptably high, more effective prevention strategies are necessary.

Keywords: attitudes

See related editorial, p. 221, Alcohol and Injury in the Emergency Department: Opportunities for Intervention. Study objective: To determine the frequency of positive alcohol readings in adolescent patients presenting for treatment of injury. Design: Patients aged 10 through 21 years were prospectively enrolled in this descriptive study. Demographic data and information about the injury were collected at enrollment. Blood ethanol concentration was measured with a saliva alcohol assay with a lower detection limit of 10 mg/dL (2 mmol/L). Setting: Enrollment was conducted at four emergency departments, an urban trauma center, an urban children's trauma center, a suburban hospital, and a rural hospital. Enrollment at each facility was conducted during two 24- hour periods for every day of the week (14 days total). Consecutive sampling was used during each enrollment period. Results: We enrolled 295 patients (92% of eligible subjects). Sixty-three percent were male; 74% were white, 19% black, 3% Hispanic, 1% Asian, and 3% from other racial groups. The mean age was 15.6±3.2 years. Fifteen patients (5%) tested positive for ethanol (range, 10 to 120 mg/dL [2 to 24 mmol/L]). Only four of these patients underwent ethanol testing as part of their medical evaluations. Of the 125 subjects aged 17 through 21 years, 14 (11.2%) tested positive for ethanol. Hospital distribution was (number of patients with positive ethanol test results): urban trauma center, 8 of 52; urban children's trauma center, 0 of 91; suburban hospital, 4 of 111; rural hospital, 3 of 41. The highest percentage of positive ethanol test results was found at the urban trauma center, where 15% of total subjects and 22% of subjects aged 17 through 21 tested positive. Injuries related to assaults and motor vehicle crashes were particularly associated with alcohol use. Conclusion: Alcohol is associated with injuries in urban, suburban, and rural settings in the older pediatric population. Alcohol use is underrecognized and should be considered in patients presenting with injuries, especially victims of assaults or motor vehicle crashes. [Meropol SB, Moscati RM, Lillis KA, Ballow S, Janicke DM: Alcohol-related injuries among adolescents in the emergency department. Ann Emerg Med August 1995;26:180-186.]

Introduction Previous research has shown that there are inequalities with regard to traffic accident risk between different social categories. This study describes the influence of the type of residential municipality (with or without deprived urban areas, “ZUS, zones urbaines sensibles”), used as an indicator of contextual deprivation, on the incidence and severity of road trauma involving people of under 25 years of age in the Rhône. Method Injury data were taken from The Rhône Road Trauma Registry. The study covers the 2004–2007 period, with 13,589 young casualties. The incidence of traffic injury of all severities were computed according to the type of municipality and the age, gender, and type of road user. The ratios of the incidences of deprived municipalities, compared with others were calculated. Subsequently the severity factors and incidences according to the severity level (ISS 1–8, {ISS} 9+) were studied. Results For the main types of road users except motorized two-wheeler users, the incidences were higher in the deprived municipalities: the greatest difference was for pedestrians, where the incidences were almost twice those of other municipalities. This excess risk, constituting a health inequality topic rarely considered, was even greater in municipalities with two or three ZUSs. It was essentially observed for minor injuries among motorists, cyclists, and pedestrians. Conclusions While the incidence increased among people less than 25 years of age, the severity of road injuries was lower in deprived neighborhoods, contrary to what is suggested by other studies. This lower severity disappeared when taking into account the crash characteristics. Impact on industry The incidence of injuries as a pedestrian, cyclist or motorist is higher among young people living in deprived municipalities. These areas should therefore be the targets of dedicated education programs, as well as further investigations about urban planning.

Keywords: Contextual deprivation

The aim of this study was to estimate the likely effect of reduced travel speeds on the incidence of pedestrian fatalities in Adelaide, Australia. The study was based on the results of detailed investigations of 176 fatal pedestrian crashes in the Adelaide area between 1983 and 1991. The method developed to estimate the effect of reduced travelling speed is described and supported by references to the published literature. A reduction in the speed limit from 60 to 50 km/h was one of four speed reduction scenarios considered. The smallest estimated reduction in fatal pedestrian collisions in the selection presented was 13%, for a scenario in which all drivers obeyed the existing speed limit. The largest estimated reduction was 48% for a scenario in which all drivers were travelling 10 km/h slower. The estimated reductions in fatalities obtained in this study are compared with those observed in places where the urban area speed limit has been lowered.

Keywords: Pedestrian safety

Data on 1008 Quebec road victims obtained from linkage of governmental records have led to different types of analyses. This article presents an application of correspondence analysis to these data. We have chosen one example with its specific results showing expected associations between variables and new, unexpected associations which are plausible. The resulting patterns indicate a clear distinction between hospitalized and non-hospitalized victims and between a rural and an urban type of road crash. This multidimensional approach gives an overall picture of the patterns among the variables studied, indicating which subsets of variables might be investigated further.

Background Numerous reports have documented a lower prevalence of seat belt use among blacks in the United States, compared with whites. Limited data suggest that black–white disparities in states with primary seat belt laws (motorists can be stopped and cited solely for violating a seat belt law) are less marked than in states with secondary laws (motorists can be cited for violating a seat belt law only if stopped for another offense). Methods Data from the Fatality Analysis Reporting System were analyzed in 2005 to compare seat belt use among 11,574 blacks and 73,639 whites aged 16 or more years killed in crashes from 1999 to 2003 in 33 states with a primary or secondary adult seat belt law and annual reporting of race for 80% or more of decedents. After stratification of states by type of seat belt law, logistic regression was used to calculate odds ratios and 95% confidence intervals (CIs) for seat belt use among blacks, relative to whites, with adjustment for age, gender, seat position, urban/rural region, and income. Results Odds ratios and 95% {CIs} for seat belt use among blacks were 1.05 (0.97–1.13) and 0.89 (0.83–0.95), in primary- and secondary-law states, respectively. Conclusions Black–white disparities in seat belt use were mitigated in states with primary seat belt laws. Only 24 states have primary laws. Enacting primary laws in other states might reduce or eliminate racial disparities in seat belt use.

Objective To illustrate mechanisms of spine fractures and the pattern of spinal injuries characterized by the major mechanisms in urban population of Iran. Methods Data regarding spinal injuries including demographics, mechanism and level of spinal injury, abbreviated injury score, associated injuries and final fate of the patients were extracted from the Iranian national trauma registry database from 1999 to 2004. Results A total of 619 patients with traumatic spine fractures were identified, of whom 68.5% were males. The peak frequency of these injuries occurred in the 21-40 year age-group. Accidental falls and road traffic crashes (RTCs) were the most common mechanisms of spinal fractures (47.2% and 44.1%, respectively). {RTCs} tended to occur in younger patients compared with accidental falls. The most common spinal region for spinal fracture was the lumbar spine (53.63%). Cervical spine fractures were significantly more common in RTCs, while lumbar spine fractures were more common in accidental falls (P<0.001). A total of 171 (27.6%) patients had associated non-spinal injuries, of whom 127 had associated extremity injuries, and 55 had head injuries. Thirty-six (5.6%) patients had spinal cord injury (SCI). The injury severity score of the {RTC} group was significantly higher than that of accidental falls (P=0.002). Fifteen (4%) patients died of traumatic injuries. The rate of death was significantly higher in {RTCs} compared with accidental falls (5.1% vs 2.1%, P=0.039). Conclusions The patterns of spinal fractures are similar to those reported from developed countries. {RTCs} tend to affect the younger age population and are associated with a higher degree of associated injuries and mortality than accidental falls. Therefore preventive strategies should be based on reduction of the number and severity of RTCs.

Keywords: Accidents, traffic

Problem Safety belt use in the United States, as measured over daylight hours, has risen steadily over recent years reaching 80% in 2004. Yet, using the National Highway Traffic Safety Administration's (NHTSA) Fatality Analysis Reporting System (FARS), safety belt use among fatally injured front seat outboard occupants of passenger vehicles was only between 42% and 46% for the years 1999 to 2003. One possible contributing factor is that safety belt use at night, when crash rates are highest, is lower than during the day. Method A full statewide nighttime belt use observation survey was conducted in 2004. This survey was conducted simultaneously with Connecticut's annual full statewide daytime belt use survey. Night belt use observations of drivers and passengers are possible using newly available near military grade night vision goggles and handheld infrared spotlights. Both day and goggle-assisted night observations were conducted at 100 observation sites in Connecticut. Procedures for day and night observations were as nearly identical as possible. Results The night belt use rate was 6.4 percentage points lower than the day rate (83.0 vs. 76.6). Consistent with belt use among Connecticut fatalities, day versus night differences were greatest in urban areas. There was evidence that day versus night differences were greater before as compared to after a May 2004 belt use enforcement program.

Keywords: Safety-belt use

Significant faunal changes reported from recent, coastal environments, which are not directly influenced by urban and industrial impact, are rarely seen. In Gullmar Fjord on the Swedish west coast, a significant foraminiferal fauna change occurred in connection with severe low-oxygen conditions that evolved in the winter of 1979/1980. A foraminiferal fauna marked by common Skagerrak–Kattegat species, which had previously characterised the deep fjord basin, was replaced by the opportunistic, low-oxygen tolerant species Stainforthia fusiformis (Williamsson). To study this phenomenon further we performed stable oxygen and carbon isotope analyses on the indicator species itself, S. fusiformis, both on specimens from sediment cores representing approximately the last 85 years and on living (stained) individuals taken from a transect across the deep fjord basin. Our purpose was to detail how and why S. fusiformis, came to dominate the fauna. The oxygen isotope results suggest that salinities and temperatures in the deep basin have been relatively constant over the last c. 85 years, while the carbon isotopes show a significant change towards more negative values in association with the faunal shift of 1979/1980. The combined results from both the cores and the surface sediments suggest that S. fusiformis did not inhabit the deep basin until 1980. Before then, almost all specimens of S. fusiformis were small sized and their carbon isotope values suggest they were re-deposited shallow-water specimens that had been transported down to the central, deep basin as part of a suspension load. After a major faunal extinction in 1979–1980, S. fusiformis of all sizes suddenly appeared in large numbers and their carbon isotopic values were similar to the signal from registered in the recent, living fauna within the deep basin. This suggests that the opportunistic S. fusiformis established itself in the deep basin as a consequence of the severe low-oxygen event and the faunal crash of the previously dominating Skagerrak–Kattegat fauna.

Keywords: Recent faunal shift

Study objectives: To document the effect of a reenacted comprehensive helmet use law on injuries and fatalities. Design: Retrospective before-and-after analysis. Setting: Two urban counties representing 40% of Nebraska's population. Participants: Six hundred seventy-one patients reported as injured to the Nebraska Department of Roads in the period from one year before through one year after the reenactment on January 1, 1989. Results: The helmet use law was temporally associated with a 26% decrease in the reported rate of motorcycle crashes in Nebraska compared with five other midwestern states. There were sharp declines in the number (and rates) of reported injured, hospital transports, hospital admissions, severe nonhead injuries, severe head injuries, and deaths. Serious head injuries (Abbreviated Injury Score, 3 or higher) decreased 22%. The percentage of injured motorcyclists with serious head injuries was significantly lower among the helmeted motorcyclists (5%) than among the unhelmeted cyclists (14%) for the two years combined. Conclusion: The reenactment of a helmet use law resulted in fewer crashes, fatalities, and severe head injuries.

Keywords: motorcycle helmets

This study was undertaken to investigate which patients 65 years of age or older have adverse outcomes after discharge from the emergency department (ED) after an injury. Patients were enrolled prospectively at an urban university center from September 15, 1996, until August 31, 1997. Patients sustaining any potentially serious form of injury were included. Data about comorbid conditions, preinjury medications, and types of injuries sustained were recorded. Patients were contacted at home at least 30 days after discharge and were questioned about their overall health, need for admission since {ED} discharge, and whether any complications developed. One hundred five consecutive patients were enrolled, but 5 patients were lost to follow-up. There were 74 low-mechanism falls (LMFs), 11 low-mechanism motor vehicle crashes (LMMVCs), 8 high-mechanism motor vehicle crashes (HMMVCs), 3 high-mechanism falls (HMFs), and 4 other types of injuries. Follow-up ranged from 30 to 147 days, with a mean of 49 days. On follow-up, 88 patients were doing well, 9 were fair, and 3 were doing poorly; of the latter, their poor health was unrelated to their injuries. Complications included 2 extremity infections and 1 poorly healing wound. Eleven patients were seen in an {ED} within the first 30 days after injury, 6 of whom for problems related to their initial injury or its management. These results show that there is a subset of elderly victims of trauma who may be safely discharged home after appropriate evaluation. Return visits to the {ED} were just as often related to comorbid conditions as to initial injury.

Keywords: Elderly

The importance of identifying factors affecting speeding is related to Police and insurance evidence of speeding as a contributor to road crashes, particularly those involving fatalities and serious injuries. Most of the literature on the causes of speeding regards speeding as a feature of risky driver behaviour or careless driving habits. Some of the literature also refers to the importance of vehicle and road environment features. Studies in Australia and overseas have looked at these factors and their relationship to spot speeds or average speed using bivariate analysis. Few studies have looked at the relative contribution of factors to driver speed compliance. In this study, an ordinary least squares regression procedure estimates that 62% of the variation in vehicle speeds can be explained by variables related to the road environment and vehicles. Moreover, it seems that drivers use posted speed limits as targets rather than delimiters and choose vehicle speeds based on factors other than the desire to be non-compliant. Policymakers intent on improving road safety should redress instances of mismatch between road design and posted speed limits and the possibilities of differential rules for rural/urban, day/night and weekday/weekend driving.

Keywords: Speeding

The objective of this study was to determine prevalence of traumatic brain injury (TBI) in an emergency department (ED) population. Questionnaires were administered to patients in an urban, university, trauma center ED. All respondents provided demographics; patients reporting {TBI} were asked age at injury, if they experienced loss of consciousness (LOC), mechanism, or if medical attention was sought. Five hundred one patients completed the survey. Forty-one percent reported TBI; 23% had {TBI} with LOC. Mean age at injury was 21.5 years. Mechanism was evenly distributed among sports, assaults, falls, and motor vehicle crashes (MVC). Medical attention was sought for 61% of injuries. Men were more likely to report {TBI} (P < .001). Medical attention was more likely if {MVC} or {LOC} and less likely in sports-injured patients (all P < .01). Twenty-five percent of patients with {TBI} sustained repeat injury by the same mechanism. Prevalence of {TBI} in this population is high. Many occur by mechanisms that potentially are preventable. (Am J Emerg Med 2002;20:177-180. Copyright 2002, Elsevier Science (USA). All rights reserved.)

Keywords: Traumatic brain injury

Background Injuries and deaths among riders of off-road motorized all-terrain vehicles are increasing in the US. We hypothesized that serious injuries in Oregon have increased among riders of both four-wheel and two-wheel vehicles. Study design We analyzed the Oregon Trauma Registry. Seriously injured patients treated in the state’s designated urban and rural trauma centers were identified using E-codes (821.0 to 821.9), which indicate whether patients were riding either an off-road all-terrain four-wheel vehicle (ATV) or off-road two-wheeled motorcycle (ORMC). Second, we performed a supplemental analysis of similar patients in the trauma registry of Oregon’s University-based tertiary care trauma center. Patients in earlier time periods were compared with those in later time periods. Results Patients injured riding off-road vehicles and needing treatment in Oregon’s trauma centers increased 76%. Sixty percent of patients were injured riding an ATV, and 35% were injured riding an ORMC. Children (aged younger than 15 years) were 20% and 23% of patients in the earlier and later years. At Oregon’s University-based Level I trauma center, in the years 2002 to 2005, more than twice as many patients needed tertiary care for severe injuries caused by off-road vehicle crashes compared with the previous 4 years. Conclusions There has been an alarming increase in the number of both {ATV} and {ORMC} riders requiring treatment in Oregon’s trauma centers. Surgeons need to join a coalition of health care providers, citizens and public officials to implement a comprehensive injury-prevention response to this epidemic.

First, the statistical analysis of injury severity is introduced by considering the following topics: (i) Interpretation of the recorded grades of injury severity (e.g. fatal, serious, slight, none) as divisions of a continuous scale, (ii) The possible presence of errors in recording injury severity, (iii) How this is used in the statistical analysis of injury severity data, including discussion of computing methods. Secondly, attention is turned to data in which the severities of injury to two people in the same crash is given. British accident data for 1969–1972 has been processed to give a cross-tabulation of the severity of injury to the driver and to the front seat passenger in four types of single-vehicle accidents (overturning and nonoverturning, each in rural and in urban areas). Three complications with this data are that the number of non-injury accidents is unknown, that the cases where a passenger was present but uninjured could not be distinguished from those where there was no passenger, and that there is inconsistency in the positioning of the thresholds separating serious from slight injury, and slight from no injury. A positive correlation between the severities of injury to the two occupants is evident in the data. This is interpreted as being largely due to the speed of the crash, and a model is developed in which the two severities jointly have a bivariate normal distribution.

Study objective: To determine the frequency of driving while impaired (DWI) charges among alcohol-intoxicated drivers injured in motor vehicle crashes (MVCs) and any differences in the group of those charged compared with those not charged. Methods: We performed a retrospective analysis of linked data from medical and judicial sources. Our setting was an urban emergency department of a trauma center serving a population of 1 million. We studied consecutive drivers injured in {MVCs} over a period of 15 months who had measured serum ethanol (BAC) levels of 100 mg/dL or higher. BAC, Trauma Score (TS), demographics, and crash data were linked to court records of charges, outcome, and prior convictions. The group of individuals who were charged with {DWI} were compared with those who were not charged. Results: One hundred eighty-seven patients were studied; 53 (28%) were charged with DWI, and 32 (17% of total) were convicted. Two (7%) of 29 patients with severe injuries, 9 (28%) of 32 with moderate injuries, and 42 (33%) of 126 with nonsevere injuries were charged (P=.004). Eighteen (16%) of 112 patients with no prior convictions were charged; 20 (56%) of 36 patients with one, 11 (52%) of 21 with two, 3 (25%) of 12 with three, and 0 of 5 with four or more prior {DWI} convictions were charged (P<.001). There were no significant differences in BAC, demographics, or other measures between the two groups. Conclusion: Alcohol-impaired drivers who require {ED} treatment for injuries sustained in an {MVC} are infrequently charged with DWI. The likelihood of a {DWI} charge diminishes with increasing severity of injury. Repeat offenders are charged more often, but the frequency of charges does not increase with increasing number of prior {DWI} convictions. [Runge JW, Pulliam CL, Carter JM, Thomason MH: Enforcement of drunken driving laws in cases involving injured intoxicated drivers. Ann Emerg Med January 1996;27:66-72.]

Urban trauma centres have recently noted a shift in the causative mechanism of facial fractures away from motor vehicle crashes (MVC) to blunt assaults (BA). This study was conducted to examine the incidence and aetiology of facial fractures at our institution as well as the relationship with alcohol and protective device use. Trauma registry records of all patients admitted to a level I trauma centre from 1 January 1988 to 1 January 1999 were reviewed. There were 13 594 trauma admissions during the 11-year period. Facial fractures were sustained by 1429 patients (10.5%) and this group forms the subject of this study. {MVC} was the predominant aetiology (59.9%) followed by {BA} (18.8%). Facial fractures were found in 9.5% of restrained {MVC} patients compared to 15.4% of unrestrained patients (P<0.00l). Non-helmeted motorcyclists were four times more likely to sustain facial fractures (4.3% vs. 18.4%) than helmeted patients (P<0.00l). 39.6% of patients in the {MVC} group were legally intoxicated compared to 73.5% in the {BA} group (P<0.00l). 45.4% of unrestrained patients with facial fractures were intoxicated compared to 11.8% of restrained {MVC} patients with facial fractures (P<0.001). {MVC} continue to be the primary aetiology of facial fractures in our trauma population. Protective devices decrease the incidence of facial fractures. Lack of protective device use and the consumption of alcohol correlate with sustaining facial fractures.

A method to collect headway (tailgating) data in an urban setting was implemented and produced reliable headway data on over 25 000 drivers. Data are reported on the effectiveness of two hand-held roadside signs admonishing drivers not to tailgate. One of these signs (that included a reference to “crashes”) had a significantly positive impact on drivers' headway. Drivers’ followed with an average headway of 2.11 s when the sign was absent compared to an average headway of 2.29 s when the sign was present. When the sign was absent, 49.4% of the drivers were in compliance with the 2-second rule compared to 57.5% when the sign was present. The percentage of drivers who followed with a headway of less than 1 s decreased from 7.3 when the sign was absent to 3.0 when the sign was present. Additionally, there was an increase of 10.6 ft in vehicle separation from baseline to intervention.

Keywords: Vehicle crashes

ResumenObjetivo Conocer los hábitos y factores de riesgo de adolescentes atendidos por los centros de salud de 2 poblaciones semiurbanas mediante una entrevista clínica estructurada con respuestas abiertas. Diseño Estudio descriptivo transversal. Emplazamiento Dos poblaciones semiurbanas de la provincia de Málaga. Participantes Adolescentes de 16 a 18 años. De los 19 cupos médicos se seleccionaron 5 mediante muestreo aleatorio estratificado por centro de salud. Se incluyeron 204 adolescentes. Resultados Tienen sobrepeso u obesidad 42,3%. La relación entre {IMC} y {TAM} fue R=0,4. Consumen fruta, verdura o lácteos menos de una vez al día el 54,2%, 57,8% y 24,5% respectivamente. No practican deporte regularmente 32,3 de los hombres y 63,5% de las mujeres. Fuman 21,8% estando asociado al nivel socioeconómico bajo (OR: 3,38 p=0,01 IC95%: 1,27–9) y abandono de los estudios (OR: 2,88 p=0,015 IC95%. 1,20–6,86). Beben el 56,3% estando asociado a haber abandonado los estudios (OR: 3,5 IC95%: 1,43–8,94). Consumían drogas ilegales el 10,6% y su grupo de amigos 36,6%. Mantuvieron relaciones sexuales sin método anticonceptivo 12,1%. No se ponen casco o cinturón el 12,4% y 13,4% respectivamente Han conducido alguna vez bebidos el 24,2%. Se han sentido alguna vez deprimidos el 20,4%. Conclusiones Las prevalencias de factores de riesgo y hábitos de vida referidos al peso, consumo de frutas, verduras y lácteos, ejercicio físico, tabaco, alcohol y trastornos de ánimo han sido semejantes a otros estudios que utilizan encuestas anónimas. Las prevalencias de consumo otras drogas ha sido menor. Objective To investigate the habits and risk factors of adolescents from two Health Centres in two semi-urban populations using a structured clinical interview with open questions. Design Cross-sectional descriptive study. Setting Two semi-urban populations from the Malaga area. Participants Adolescents aged between 16 and 18 years old. We selected 5 medical clinics out of the 19 clinics in the Health Centres, using stratified random sampling. A total of 204 adolescents were included, with 62 (30.39%) of them not attending. Outcomes 42.3% were overweight or obese. The {BMI} and {MBP} ratio was R=0.4 They ate fruit, vegetables or dairy products at least once a day 54.2%, 57.8% and 24.5%, respectively. 32.3% of the male teenagers and 63.5% of females did not exercise regularly. 21.8% were smokers, and this was related to a low socio-economical level (OR: 3.38 P=0.001 95% CI: 1.27 to 9) and with abandoning education (OR: 2.88 P=0.015 {CI} 95%. 1.20 to 6,86). 56.3% usually drink and this habit was also related to abandoning education. (OR: 3.5 95% CI: 1.43 to 8.94). 10.6% of the teenagers consumed illegal substances and their group of friends in 36.6% of the cases. 12.1% had unprotected sex. 12.4% and 13.4% did not use a crash helmet or seat belt, respectively. 24.2% have driven in a drunken state at some point. 20.4% have felt depressed at least once. Conclusions Risk factors and life style habits prevalent in reference to weight, fruit, vegetables and dairy products consumption, sport, smoking, alcohol and depression problems have been similar to the ones found in other studies that have used anonymous surveys. Prevalence of substance abuse has been lower.

Keywords: Adolescentes

Introduction: This research studied the effectiveness of Florida’s mandatory helmet law for children and a community bicycle safety campaign promoting helmet use. Children’s use of helmets before and after the law’s enactment and the type and extent of head injuries sustained in bicycle crashes were evaluated. Methods: The trauma and medical records from Broward General Medical Center’s Pediatric Referral Trauma Center provided demographic data, injury severity scores, and information on the type and extent of head injuries sustained. Data were compared using independent sample t tests and Pearson χ2 statistics with .05 as the significance level. Results: Each group consisted of 72 children, predominantly 7- to 12-year-old boys. Known helmet use rose from 5.6% to 20.8%, with children aged 10 to 12 years having the greatest increase in helmet use (27%). Helmet use rose in urban and suburban areas. Changes in the type and extent of head injuries were mixed. Injury severity scores were higher for nonhelmeted children in the after-law group. Discussion: Although helmet use increased, especially among the 7- to 12-year-olds targeted during the bicycle safety campaigns, bicycle helmet use remains too low, and nonhelmeted children continue to have a higher risk for serious injuries. Community bicycle safety programs that promote helmet use remain an important adjunct to mandatory helmet use laws. (J Emerg Nurs 1999;25:496-500)

In this study we have tried to determine physician success in the collection of injury data during the emergency department visit. Prospective data were collected from all children between the ages of 0 to 18 treated for an injury. Data were collected at the time of the visit and by chart review the next day. At an urban, university-affiliated, children's hospital, data were collected on 2,156 injured children. Fifty-one percent of the data forms were completed by the treating physician. Physician completion rate was lower on the weekends (46%) than on weekdays (52%, P = .02). The most common mechanisms of injury were falls (34%), motor-vehicle crashes or pedestrians struck (13%), and nonintentional struck by blunt object (12%). The most common mechanism of injury in all age groups was falls. Our results demonstrate that emergency physicians are not successful data collectors. However, when physician data collection is combined with next-day review of patient records, virtually 100% of patients are captured. Active emergency department data collection is important because in contrast to studies which use hospital discharge and mortality data, we found that overall falls account for more injuries presenting to the {ED} than transportation-related causes. An active surveillance system in emergency departments that does not require extra work on the part of the treating physician would be ideal and may give a more comprehensive description of the scope of the injury problem.

Keywords: Injury surveillance

Red light cameras are increasingly being used to supplement police efforts to enforce against noncompliance with traffic signals—a substantial contributing factor in urban motor vehicle crashes. Camera enforcement is intended to modify driver behavior through both general deterrence and punishment of individual violators. A before/after quasi-experimental design with controls was employed to evaluate the influence of a red light camera enforcement program on red light violation rates in the city of Oxnard, CA. A total of 14 intersections (nine camera sites, three non-camera sites, and two control sites) were studied. Overall, the red light violation rate was reduced approximately 42% several months after the enforcement program began. Increases in driver compliance with red lights were not limited to the camera-equipped intersections but spilled over to nonequipped intersections as well. Results of public opinion surveys conducted approximately 6 weeks before, 6 weeks after, and 6 months after the camera enforcement program began indicated that nearly 80% of Oxnard residents support using red light cameras as a supplement to police efforts to enforce traffic signal laws.

Keywords: Urban crashes