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Recently, the severity of injuries resulting from traffic crashes has been extensively investigated in numerous studies. However, the number of studies that addressed the severity of the run-off-road (ROR) crashes is relatively low. In the Emirate of Abu Dhabi (AD), approximately 22% of the total serious crashes and fatalities that occurred from 2007 to 2013 were ROR crashes. Despite these facts and the uniqueness of the composition of licensed drivers in AD (approximately 87% of them are non-Emiratis), the factors affecting the occurrence and severity of ROR crashes in AD have not been explicitly addressed in any prior studies. Therefore, this study aims to investigate the characteristics of at-fault drivers involved in ROR crashes in AD, the nature and main causes of those crashes. In this regard, conditional distribution and two-way contingency tables were developed. In addition, this study aims to identify and quantify the factors affecting the severity of ROR crashes such as driver, road, vehicle and environment factors. To achieve this goal, ordered probit model approach was employed. Crash data for a total of 3819 ROR crashes that occurred in AD were employed in the analysis. The results indicated that driver factors (carelessness, speeding, and nationality), vehicle characteristics (vehicle type), and road and environment factors (road type, crash location and road surface condition) were the significant factors influencing the severity of ROR crashes in AD. Countermeasures to improve traffic safety and reduce numbers and severity of ROR crashes in AD were discussed. Key words: run-off-road crashes, crash severity, traffic safety, ordered logit model. La gravite des blessures causees par des accidents de la route a recemment fait l'objet de nombreuses etudes approfondies. Cependant, assez peu d'etudes se sont interessees a la gravite des accidents provoques par une sortie de route (SDR). Dans l'emirat d'Abou Dabi (AD), environ 22 % des accidents graves et mortels denombres entre 2007 et 2013 etaient des accidents causes par une SDR. Malgre cela et en depit de la composition singuliere de la population des conducteurs titulaires d'un permis de conduire dans l'emirat d'AD (environ 87 % d'entre eux n'etant pas des Emiratis), les facteurs qui influent sur le nombre et la gravite des accidents dus a une SDR n'avaient jamais ete serieusement etudies auparavant. Par consequent, la presente etude vise a etudier les caracteristiques des conducteurs de conducteurs responsables impliques dans des accidents provoques par un SDR dans l'emirat d'AD ainsi que la nature et les principales de ces accidents. Pour ce faire, des distributions conditionnelles et des tableaux de contingence a double entree ont ete crees. La presente etude a egalement pour objectif de determiner et de quantifier les facteurs qui influent sur la gravite des accidents causes par une SDR, tels que le conducteur, la route, le vehicule et les facteurs environnementaux. Pour atteindre un tel objectif, une methode sur un modele probit ordonne a ete utilisee. Pour realiser cette etude, on s'est servi des donnees relatives a 3819 accidents causes par une SDR et survenus dans l'emirat d'AD. Les resultats ont montre que les facteurs associes aux conducteurs (manque de vigilance, vitesse de conduite et nationalite), les caracteristiques des vehicules impliques (type de vehicule) et les facteurs environnementaux et lies a la route (type de route, lieu de l'accident et etat de la surface de la route) influaient beaucoup sur la gravite des accidents provoques par une SDR et survenus dans l'emirat d'AD. Des mesures visant a ameliorer la securite routiere et a reduire le nombre et la gravite des accidents dus a une SDR dans l'emirat d'AD sont egalement presentees. [Traduit par la Redaction] Mots-cles: accidents causes par une sortie de route, gravite des accidents, securite routiere, modele logit ordonne., Introduction Run-off-road (ROR) crashes are considered as one of the major causes of fatalities and serious injuries in traffic crashes around the world. Run-off-road crashes occur when the driver loses [...]

The number of automobile recalls in the United States has substantially increased over the last two decades, and after a record of over 30 million cars recalled in 2004, in the last few years it has consistently reached between 15 and 17 million, and in 2010 alone 20 million cars were recalled. Toyota's recall crisis in 2010 illustrates how recalls can affect a large number of American drivers and the defects connected to them can result in loss of life and serious accidents. However, in spite of the increase in public concern over recalls and the loss of property and life attached to them, there is no empirical evidence of the effect of vehicle recalls on safety. This paper investigates whether vehicle recalls reduce accidental harm measured by the severity of injuries in vehicle accidents. The results of our analysis show that if a recall for a new-year model is issued, then the severity of injuries of accidents continuously diminishes during the first year after the recall, something we do not find among cars not subject to recalls. This is because defects are repaired over time but also because drivers react by driving more carefully until the defects are fixed. To minimize the losses attached to having dangerously defective cars on our roads, both quick and timely recall issuance are needed and more detailed information on defects should be delivered to owners of defective vehicles. The latter can be made possible through simple but important policy changes by the U.S. government regarding recall information sharing with drivers and insurance companies. (JEL L51, L62), I. INTRODUCTION The National Highway Traffic Safety Administration (NHTSA) reports in its 2009 annual report that in 2008, 37,261 people were killed in the 5,811,000 police-reported motor vehicle traffic crashes. [...]

Intersection-related crashes account for approximately 31% of fatal crashes in Minnesota and roughly 37% of those occurred at night, dusk, or dawn. Nationally, intersection-related fatal crashes accounted for 21% of all fatal crashes and 40% of those crashes occurred during dark, dusk, or dawn light conditions while only 25-33% of the vehicle miles traveled occur at night. Furthermore, Minnesota experienced 70% of its fatal crashes in rural areas, as compared to 58% nationally. As a result, rural intersections at night are at higher risk for fatal crashes than other locations in Minnesota. This research was part of Research Rep. No. MN/RC- 2006-35, 'Safety impacts of street lighting at isolated rural intersections--Part II.' This research evaluated the effectiveness of roadway lighting in reducing nighttime crashes at isolated rural intersections. A before-and-after study was used to evaluate the impact of lighting at 33 intersections with 3 years of before data and 3 years of after data. A Poisson regression model evaluated the change in the expected number of crashes after installation of lighting. Crash rate was calculated using this information and used to compare day versus night since volumes are expected to differ. Results indicated that the night crash rate was 37% lower after lighting was installed and was statistically significant. The change in daytime crash rate from the before to after period was 4% but was not statistically significant indicating that there was no overall change in crash rate during the analysis period due to other factors. DOI: 10.1061/(ASCE)TE.1943-5436.0000161 CE Database subject headings: Streets; Light; Intersections; Traffic safety; Statistics; Rural areas; Minnesota. Author keywords: Street lighting; Intersection; Safety; Statistical model.

In this paper, a subframe type fuel tank module was proposed and evaluated to increase the vehicle safety and the design flexibility against rear crash of automotive vehicles. In order to minimize the deformation of the fuel tank during rear crash, crash simulations and optimization of design parameters associated with the subframe type fuel tank module were carried out using the robust design method. A rear crash test was conducted with a midsize passenger car, and the measured deformations of the fuel tank showed an excellent agreement with the simulation. It was also found that the optimized design of the subframe type fuel tank reduced the deformation of the fuel tank up to a maximum of 27.5 times, compared with the deformation in the conventional design. The proposed design of fuel tank not only provides the design flexibility but fulfills the requirements of the revised Federal Motor Vehicle Safety Standards Sec. 301. [DOI: 10.1115/1.4001344] Keywords: rear crash, robust design, fuel spillage, subframe type fuel tank, design flexibility

Large speed differentials between highway segments are associated with an increase in the number of accidents. Traditional speed differential measures, derived from single-level linear regression models, suffer from serious deficiencies, namely underestimating the speed differential (due to intracorrelated data) and inflating the adequacy of the model's explanation (due to aggregate data). High-quality speed differentia] predictions are highly desirable right from the initial design phase, but the estimation process is not straightforward, and decision makers must recognize that speed differential predictions are subject to considerable uncertainty. This paper compares four models; two single-level models, a conventional multilevel model, and a Bayes multilevel model. The results show empirically that multilevel models increase the accuracy and precision of estimates of speed differentials, possibly with fewer data. The paper introduces a new, easy to interpret speed consistency measure that simply represents the probability that a vehicle exceeds a certain speed differential. This measure is calculated using a multilevel model and takes into account the uncertainty in the estimates of speed differentials. Overall, we show that a multilevel modeling approach can improve the quality of decision making that makes use of speed differential information in road design and road safety. Key words: speed, highway safety, statistical models, road design. Les grands differentiels de vitesse entre des troncons d'autoroute sont relies a une augmentation du nombre d'accidents. Les mesures habituelles de mesure de la vitesse, derivees de modeles de regression lineaire a un niveau, presentent de graves manques : sous-estimation du differentiel de vitesse (en raison de l'intra-correlation des donnees) et l'exageration de la pertinence de Implication du modele (en raison des donnees globales). Il serait souhaitable d'avoir des previsions du differentiel de vitesse de grande qualite des la phase de conception initiale, mais le processus d'estimation n'est pas simple et les decideurs doivent reconnaitre que les previsions du differentiel de vitesse sont sujettes a une grande incertitude. Le present article compare quatre modeles : deux modeles a un niveau, un modele convenlionnel a plusieurs niveaux, et un modele de Bayes a plusieurs niveaux. Les resullais montrent de maniere empirique que les modeles a plusieurs niveaux augmentent l'exactirude et la precision des estimations des differentiels de vitesse, possiblement en utilisant moins de donnees. Cet article introduit une nouvelle mesure facile a interpreter de la Constance de la vitesse qui represente simplement la probability qu'un vehieule excede un certain differentiel de vitesses. Cette mesure est calculee en utilisant un modele a plusieurs niveaux et elle tient compte de l'incertitude dans les estimations des differentiels de vitesse. De maniere generate, nous montrons qu'une approche de modelisation a plusieurs niveaux peut ameliorer la qualite de la prise de decisions qui se servent des differentiels de vitesse lors de la conception des routes et pour la securite routiere. Mots-des : vitesse. securite routiere. modeles statistiques, conception routiere., [Traduit par la Redaction] Introduction The concepts of design speed and speed consistency are well established in the highway design process (Fitzpatrick et al. 2000; AASHTO 2004). Speed consistency is [...]

The danger of alcohol- and drug-impaired driving implies that policies that reduce substance abuse can save lives. We study this issue in small U.S. counties where access to substance abuse treatment can be measured directly through the presence of treatment facilities. We find that placing an additional treatment clinic in a county reduces the number of alcohol-related motor vehicle fatalities by 15%. An additional outpatient clinic, which specializes in treating the local population, reduces the overall number of alcohol-related deaths by 26%. In the counties that we study, this reduction in alcohol-related accidents saves 0.66 lives per county per year. JEL Classification: I1, I18, K42, 1. Introduction In recent years, motor vehicle accidents have led to over 40,000 deaths annually in the United States, and alcohol-related accidents account for about 40% of these deaths. Legally [...]

Numerous factors may contribute to high-severity crashes in highway work zones. Identifying these factors and then alleviating their impact is a challenging task that traffic engineers and researchers have to confront. In this study, the work zone risk factors that could increase the probability of causing fatalities when severe crashes occur were examined using a comprehensive approach. The researchers first identified the significant risk factors based on a screening process that incorporates both statistical analyses and empirical research findings. They then systematically investigated these factors using logistic regression and frequency analysis techniques. The severe crashes including the fatal crashes between 1998 and 2004 and injury crashes between 2003 and 2004 in Kansas highway work zones were used in the study. The assessed risk factors included variables describing driver characteristics, environmental conditions, crash road conditions, and other crash information. The results of this study will help traffic engineers to understand these risk factors and how the factors could increase the likelihood of having fatalities when a severe crash occurs in a work zone. Consequently, effective safety countermeasures may be designed at the work zone planning and installation stages to prevent safety deficiencies. DOI: 10.1061/(ASCE)TE.1943-5436.0000055 CE Database subject headings: Construction sites; Highway and road construction; Safety; Human factors; Errors; Risk management; Logistics; Statistics.

Objectives. We examined the long-term effects of the 1995 repeal of federal speed limit controls on road fatalities and injuries in fatal crashes. Methods. We used a Poisson mixed-regression model to assess changes in the number of fatalities and injuries in fatal crashes between 1995 and 2005 on rural interstates, where all US states have raised speed limits since the repeal, as well as on urban interstates and noninterstate roads, where many states have raised speed limits. Results. We found a 3.2% increase in road fatalities attributable to the raised speed limits on all road types in the United States. The highest increases were on rural interstates (9.1%) and urban interstates (4.0%). We estimated that 12545 deaths (95% confidence interval [CI]=8739, 16352) and 36583 injuries in fatal crashes (95% CI=29322, 43844) were attributable to increases in speed limits across the United States. Conclusions. Reduced speed limits and improved enforcement with speed camera networks could immediately reduce speeds and save lives, in addition to reducing gas consumption, cutting emissions of air pollutants, saving valuable years of productivity, and reducing the cost of motor vehicle crashes. (doi:10.2105/AJPH.2008.153726

The context of this research is the governmental targeting of road casualty reductions in England. Local authorities have a major role to play in achieving such targets and this research explores the relationships between road casualties and local authority characteristics such as population, road networks, traffic, and geography. Regression models are identified for types of road casualty to provide local area expectations against which observed numbers can be compared. A number of issues are identified that raise concerns about the current methods adopted for assessing road safety performances and about the implementation of this approach at local levels. These issues include the large impact on assessments of judgements of casualty severity and of estimates of starting point casualties when estimating reductions over time. This study leads to recommendations for ways in which current approaches to road casualty appraisal might be improved. doi: 10.1057/palgrave.jors.2602623 Keywords: accidents; road transport; regional studies

Overtaking and lane changing are very dangerous driving maneuvers due to possible driver distraction and blind spots. We propose an aid system based on image processing to help the driver in these situations. The main purpose of an overtaking monitoring system is to segment the rear view and track the overtaking vehicle. We address this task with an optic-flow-driven scheme, focusing on the visual field in the side mirror by placing a camera on top of it. When driving a car, the ego-motion optic-flow pattern is very regular, i.e., all the static objects (such as trees, buildings on the roadside, or landmarks) move backwards. An overtaking vehicle, on the other hand, generates an optic-flow pattern in the opposite direction, i.e., moving forward toward the vehicle. This well-structured motion scenario facilitates the segmentation of regular motion patterns that correspond to the overtaking vehicle. Our approach is based on two main processing stages: First, the computation of optical flow in real time uses a customized digital signal processor (DSP) particularly designed for this task and, second, the tracking stage itself, based on motion pattern analysis, which we address using a standard processor. We present a validation benchmark scheme to evaluate the viability and robustness of the system using a set of overtaking vehicle sequences to determine a reliable vehicle-detection distance. Index Terms--Collision-avoidance systems, lane-change decision aid systems, machine vision, safety.

Access to freeways is provided through interchanges to maintain the design concept of uninterrupted traffic flow. Therefore, provision of an appropriate entrance ramp and acceleration lane geometry that allows the entering vehicle to accelerate to a speed closer to the through lane speed is important for comfortable and safe merging maneuvers. In this paper, speed and traffic data were collected from 23 merging sites on Highway 417 located within the City of Ottawa, Canada, to study the traffic behavior at freeway merge areas. Analysis of traffic behavior showed that merging speed depends on both ramp and speed-change lane (SCL) geometrics. Lower merging speed was shown to be associated with higher collisions on the acceleration lanes. Right lane traffic volume and merging speed of entering vehicles were shown to significantly affect right lane speed along the acceleration lane. In addition, several statistically significant models were developed for the prediction of 85th percentile passenger car right lane speed, merging speed, merging distance, and acceleration on the SCL. A safety performance model was also developed to relate the total number of collisions on the acceleration SCL to the features of the merge area including the merging speed. CE Database subject headings: Acceleration; Driver behavior; Ramps; Traffic safety; Traffic speed; Vehicles.

Although geographic information systems (GISs) have been applied in different areas of transportation, full use of their potential in speed profile analysis and highway design consistency studies has yet to be made. The possibilities that GISs offer for analysis and the increasing number of highway inventories supported by such systems, including traffic data and crash rates, suggest that the implementation of a highway design consistency analysis module within a GIS will facilitate and improve road safety studies. It is with this aim that a GIS-based computer system that builds vehicle speed profiles and analyzes highway design consistency has been developed, in which an operating speed prediction model, acceleration/deceleration rates, and other features can be configured by the engineering user in order to obtain an analysis that is more representative of drivers and local conditions. Application of this system to the study of the design consistency of highways is described, using three examples. DOI: 10.1061/(ASCE)0887-3801(2008)22:5(325) CE Database subject headings: Geographic information systems; Highway and road design; Safety; Traffic speed; Evaluation.

Detailed modeling of traffic crashes occurring on urban limited access highways in Florida was conducted to determine the influence of various geometric and traffic variables on crash occurrence with special emphasis on presence of truck lane restriction. The geometric variables modeled were length of each segment, number of lanes, number of interchanges, number of ramps, lane width, and shoulder width. The traffic variables modeled were average annual daily traffic, percent of trucks, operating speeds, presence of high occupancy vehicle lane, and presence of truck lane restriction lanes. Also included in the modeling were variables accounting for differences in driving behavior in different urban regions of the State of Florida. The results showed that, although statistically insignificant (p [less than or equal to] 0.808), the presence of truck lane restriction had a negative modeling coefficient suggesting that sections with truck lane restriction tended to have less crashes than sections without truck lane restriction. This tendency was confirmed with a marginal effect analysis which showed that implementing truck lane restriction on a Florida urban freeway would have an annual effect of reducing crashes by approximately 4%. These results are in line with the results reported in a number of previous studies investigating the efficacy of truck lane restriction. In addition, various modeling paradigms revealed that there were regional differences in crash occurrence in which the probability of crash occurrence increased from the Orlando area, the Jacksonville area, the Tampa area, the to tricounty area of Palm Beach, Broward, and Miami-Dade, in that order. DOI: 10.1061/(ASCE)0733-947X(2008) 134:7(297) CE Database subject headings: Traffic accidents; Safety; Transportation management; Trucks; Florida; Urban areas.

Work-zone safety continues to be a priority and a concern for the Federal Highway Association as well as most state departments of transportation. The main objective of this study is to uncover work-zone freeway crash characteristics to help develop countermeasures that limit work-zones' hazards. The Florida Crash Records Database for years 2002, 2003, and 2004 was utilized for this study. Conditional logistic regression along with stratified sampling and multiple logistic regression models were estimated to unveil work-zone freeway crash traits. According to the models' results, roadway geometry, weather condition, age, gender, lighting condition, residence code, and driving under the influence of alcohol and/or drugs are significant risk factors associated with work-zone crashes. CE Database subject headings: Highway construction; Construction sites; Accidents; Statistics; Regression models; Driver behavior.

The need for safety assessment tools for long-range transportation planning at statewide and metropolitan levels received serious recognition when the Transportation Equity Act for Twenty First Century established a requirement related to safety considerations in the planning process of metropolitan planning organizations (MPO) and state Departments of Transportation. The latest legislation titled 'Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users' also has confirmed this requirement. However, most MPOs do not currently assess the safety consequences of alternative transportation systems, and one of the reasons is the lack of suitable methodology. The goal of the research on which this paper is based was to develop practical tools for assessing safety consequences of freeways in the context of long-range urban transportation plans. Data for crashes, identified by freeway segments, were obtained from the North Carolina Department of Transportation and Tennessee Department of Transportation. The researchers used the negative-binomial regression modeling approach to develop separate models to predict number of crashes for different levels of crash severity for noninterchange segments, and interchange segments, respectively. A major consideration for the selection of independent variables of the models was planners' ability to forecast future values of the model variables for alternative highway networks. The paper presents crash prediction models that MPO planners can use to evaluate the safety impact of alternative freeway networks when comparing their costs and benefits in the long-range planning context. These models are not meant to be used for analyzing detailed design features of urban freeways during project development stage, which usually is the responsibility of state Department of Transportation. DOI: 10.1061/(ASCE)0733-947X(2008) 134:3(111) CE Database subject headings: Accident prevention; Planning; Regression models; Safety; Urban areas; Interchanges.

Advances in machine vision techniques have led to algorithms and integrated systems that can be applied in transportation engineering to improve surveillance and control. Despite these advances, certain problems in the effective integration of machine-vision based systems at complex intersections and complex freeway sections still remain. These are related to increasing system performance in the identification, analysis, and detection of the traffic state in real time. This work examines the feasibility of providing transformed visual input to existing machine-vision based systems, in order to gain increased efficiency and cost effectiveness of integrated transportation systems. Two transformations are developed, homography-based transformation and panoramic image reprojection. Homography-based transformation operates on video of the road scene, provided by classical cameras, and seeks to transform any view to a top-down view. This transforms the three-dimensional problem of image analysis for, e.g., road event detection to a two-dimensional one. Panoramic image reprojection employs panoramic cameras to reduce required hardware, and the complexity and cost incurred in obtaining the desired road view. The image reprojection technique allows the reconstruction of undistorted, perspectively correct views from panoramic images in real time. Tests at sites in Spain, the United Kingdom, and Greece are performed on-line and off-line in combination with operating machine-vision based incident detection systems. Test results indicate that the two methods simplify the input provided to machine vision, and reduce the workload and amount of hardware in implementing complex machine-vision based systems for incident detection. Both modules can be integrated into incident detection systems to improve their overall efficiency and ease of application. DOI: 10.1061/(ASCE)0733-947X(2006) (837) CE Database subject headings: Imaging techniques; Transportation systems; Traffic accidents; Algorithms.

Single-vehicle crash data for 2000 from Taiwan's Road Accident Investigation & Reporting System were employed to compare fatality risk factors between non-motorcycle drivers and motorcyclists. On average, motorcyclists had approximately a three times higher fatality risk than non-motorcycle drivers after adjusting for the driving mileage. Two respective logistic regression models for these two categories of drivers indicated that some common features, such as being male, a higher age, and crashes occurring between the hours of 2200 and 0600 revealed a greater likelihood of fatality. On the other hand, the risk discrepancies between these two drivers included the restraint-use effect, speeding, and impairment as the main crash cause, roadway class, and vehicle type. To reduce the high risk of fatality sustained by these two classes of drivers, enhancing the driver's seatbelt-use rate, the management of running speed, the rider's risk perceptions, and the road quality and facilities of the lowest roadway class are particularly recommended. CE Database subject headings: Risk management; Fatalities; Traffic accidents; Taiwan.

The effectiveness of cellular radio networks is examined in relation to the motor vehicle accidents in the United States. The adverse effect of the location of base stations and channel allocations on this effectiveness is analyzed and a mixed integer-programming model is proposed for resolving the problems.

A research on the marginal effects of changes in the vehicle mix on road safety is presented. It is concluded that increasing the number of cars and buses would reduce the number of fatal crashes while increasing the number of motorcycles, trucks, sport utility vehicles and vans will increase the frequency of fatal crashes.

The impact of a paid advertising campaign targeted at reducing youthful male drinking-driving behavior is examined using (1) pretest and posttest sample surveys taken at both a campaign site and a control site and (2) time series intervention modeling of monthly traffic accident data from both sites. These compatible analyses provide collaborative evidence that the advertising campaign reduced youthful male drinking and driving behavior and, consequently, traffic accidents. KEY WORDS: Alcohol abuse; Drinking and driving; Public service advertising; Social marketing; Time series intervention analysis., Each year, drinking and driving behavior are responsible for at least 24,000 traffic fatalities and cause more than one-half million injuries. Unfortunately, a disproportionate number of these accident victims are [...]

The article discusses the increased risks of injury and death posed by those individuals who are driving and are distracted by things like talking on a cell phone or even sending a text message. The increasing number of accidents caused due to distracted driving has led the U.S. government and the National Safety Council to set up an organization called FocusDriven, to reduce the prevalence of distracted driving.