Higher Crash Rates Research Articles

Long-term effect of the North Carolina graduated driver licensing system on licensed driver crash incidence: A 5-year survival analysis

Several studies document the success of graduated driver licensing (GDL) systems in reducing young teen crash rates, but it is not yet clear whether any portion of the crash reduction is achieved by producing more capable drivers. The purpose of this study was to determine whether young teen drivers licensed under the North Carolina GDL system remain crash-free longer than those licensed prior to GDL, independent of the crude reductions in exposure (i.e., decreasing and delaying licensure) that may be responsible for most documented effects of GDL. Survival analysis was used to compare retrospective cohorts of 16–17 year olds before ( n = 105,569) and after ( n = 327,054) the North Carolina GDL system was implemented. The crash incidence of GDL-licensed 16–17 year olds (combined) was 10% lower than that for pre-GDL teens for at least 5 years after being licensed to drive independently (hazard ratio [HR] = 0.90; 95% confidence interval [CI] = 0.89, 0.91). However, more refined analysis revealed the reductions to only be among females (7%; HR = 0.93; CI = 0.91, 0.94) and males (15%; HR = 0.85, CI = 0.84, 0.87) licensed at age 16 and not among females (0%; HR = 1.00; CI = 0.95, 1.06) and males (0%; HR = 1.00; CI = 0.92, 1.09) licensed at age 17. Sixteen-year-old drivers licensed under the North Carolina GDL system experienced lower first-crash incidence during the first 5 years of unsupervised driving than did those licensed under the previous system. The benefits are greater for males, who tend to have higher crash rates. The findings contradict conventional wisdom that the entire benefit of GDL results merely from decreasing or delaying licensure among young drivers.

Increasing Seat Belt Use by Teens

Teenage drivers (age range, 16–20 years) have the highest crash rate per mile driven among all age groups and are less likely to use seat belts than

Khat, driver impairment and road traffic injuries: a view from Ethiopia

This article comments on the problem of driver impairment due to khat and the resulting road traffic injuries in Ethiopia. The authors maintain that research into traffic accidents has been dominated by issues of concern to high-income countries while issues of primary concern to developing countries have been neglected. One of these is the stimulant effect of the leaf khat (Catha edulis, also spelled qat or kat), commonly chewed by drivers in Ethiopia and other countries in eastern Africa and the Arabian peninsula. The authors first review the traffic and safety statistics from Ethiopia, which has some of the most dangerous roads in the world. Although there is no equipment available to law enforcement officers to measure drug use, both police and government officials as well as the general public believe khat use is a major cause of driver error and crashes. Khat is a stimulant and its regular use as been integral to social life in Ethiopia. The use of khat initially leads to euphoria, feelings of alertness and excitability, typically followed by irritability and insomnia and, later, lethargy. The authors review the legalities of growing and using khat in Ethiopia; the inclusion of khat use under a little-enforced law regarding driving under the influence of mind-affecting drugs; how Ethiopia can learn from the international experience of dealing with driving under the influence (DUI) problems; and the need for more road safety research, particularly regarding khat-related impairment. The authors suggest that khat-related impairment could be an overlooked contributor to the extraordinarily high traffic crash and fatality rates in Ethiopia and other countries in eastern Africa. They call for research in three areas that could be used to support effective policy responses: which drivers chew khat; when, and under what circumstances, they chew it; and the beliefs that drivers have about the effects of khat on their driving ability.

Driving after concussion: The acute effect of mild traumatic brain injury on drivers' hazard perception.

No research has examined whether individuals recovering from a recent mild traumatic brain injury (MTBI) are safe to drive, despite cognitive impairment being a common consequence soon after MTBI. This study examined the acute effect of MTBI on drivers' hazard perception, which is defined as drivers' ability to search the road ahead to rapidly identify potentially dangerous traffic situations. Poorer hazard perception has been associated with higher crash rates in a number of studies. Forty-two patients with MTBI and 43 patients with minor orthopedic injuries were recruited from the emergency department of a large metropolitan hospital within 24 hours of injury. Participants completed a computerized hazard perception test, in which they watched videos of genuine traffic scenes filmed from the driver's point of view. They were required to use the computer mouse to click on potential traffic hazards as early as possible. Participants with MTBI were significantly slower to respond to traffic hazards than participants with minor orthopedic injuries (p = .03, d = .48). This study provides the first indication that within the acute stage postinjury, MTBI is associated with impairment in a crash-related component of driving. This suggests that patients with MTBI should be advised to refrain from driving for at least the first 24 hours' postinjury.

Modeling and Evaluating Safety Impacts of Access Management Features in the Las Vegas, Nevada, Valley

This paper presents results of a study that developed statistical models that relate access management (AM) features to traffic safety in midblock sections of street segments. The objective of the study was to evaluate and quantify the impact of the AM features on traffic crashes in the midblock sections. Models were calibrated for two main types of median treatments for street segments: raised medians (RM) and two-way left-turn lanes (TWLTL). Other AM features considered were signal spacing and the densities of driveways, median openings, and unsignalized crossroads. Separate models were developed to determine the impact on total crash rates and types and severity of crashes. The study results confirmed the intuitive expectation that these AM features do have a significant impact on safety. They show that the crash rate of segments with RM was lower by 23% as compared with segments with TWLTL. The results also showed that higher densities of driveways, unsignalized crossroads, and median openings resulted in higher crash rates and severity. For example, for segments with RM, each additional median opening per mile resulted in a 4.7% increase in the total crash rate. These results are compared with the results of previous similar studies. It is anticipated that the results of this study will assist local jurisdictions in the Las Vegas, Nevada, Valley in developing new AM policies and programs.

Role of Poverty in California Teenagers’ Fatal Traffic Crash Risk

Teenagers’ high rates of motor vehicle crashes, accounting for 40% of external deaths among 16-19 yearolds, have been ascribed largely to inherent “adolescent risk-taking” and developmental hazards. However, the fact that compared to adults 25 and older, teenagers are twice as likely to live in poverty and low-income areas, risk factors for many types of violent death, has not been assessed. This paper uses Fatality Analysis Reporting System data on 65,173 fatal motor vehicle crashes by drivers in California’s 35 most populous counties for 1994-2007 to analyze fatal crash involvements per 100 million miles driven by driver age, county, poverty status, and 15 other traffic safety-related variables. Fatal crash rates were substantially higher for every driver age group in poorer counties than in richer ones. Multivariate regression found socioeconomic factors, led by the low levels of licensing and high unemployment rates prevalent in low-income areas, were associated with nearly 60% of the variance in motor vehicle crash risks, compared to 3% associated with driver age. The strong association between fatal crash risk and poverty, especially for young drivers who are concentrated in high-poverty brackets and low-income areas, suggests that factors related to poorer environments constitute a major traffic safety risk requiring serious attention.

Relationship between Access Management and Other Physical Roadway Characteristics and Safety

In the past, one of the primary focus areas for access management research has been on the physical characteristics of a roadway (i.e., signal spacing, unsignalized access spacing, and median openings) and their associated safety benefits. Although the literature has documented these characteristics as a function of safety, previous research has not investigated the specific relationships between the various other physical characteristics of the arterial roadway network and safety. The objective of this research was to examine the relationships between physical characteristics of the arterial roadway network (including access management related characteristics) and safety. Additionally, a process whereby these relationships could be identified not only for crash rates, but for collision type and crash severity (as a function of crash frequency) was developed. Statistical analyses showed that the specific access management related characteristics were positively related with increased crash rate and severity. Furthermore, land use was identified to play a significant role in the safety of arterial roadways as arterial roadway segments with adjacent commercial land use tended to have higher crash rates and severity.

The role of the built environment in explaining relationships between perceived and actual pedestrian and bicyclist safety

While the conventional approach to safety planning has emphasized crash analysis with police-reported crash information, transportation professionals increasingly recognize the importance of proactively identifying potential crash risk and considering environmental characteristics. In a proactive approach, individuals’ perception of crash risk provides important information in identifying potential crash risk. As built environment characteristics influence the levels of pedestrian and bicycle safety, this study examined how perceived and actual crash risk are related with each other and with respect to built environmental characteristics. Our results showed that residents who live in low density-single residential neighborhoods are more likely to perceive their neighborhood as dangerous relative to residents of compact, mixed-use neighborhoods even though the latter exhibited higher actual crash rates. The results of path analyses confirmed that a simultaneous but opposite relationship exists between perceived and actual crash risks. Our results indicate that higher actual crash risk increases perceived crash risk, while higher perceived crash risk is negatively associated to actual crash rates. Consequently, low density and non-mixed land uses increase individuals perception of crash risk, and increased perception of risk and unfriendly environment for pedestrian and bikers reduces actual crash rates as a result of behavioral changes. From a policy standpoint, more attention and proactive interventions are desirable in suburban areas beyond the areas with high crash rates, as some of these areas have high-perceived risks.

The Relationship between Impaired Driving Crashes and Beliefs about Impaired Driving: Do Residents in High Crash Rate Counties Have Greater Concerns about Impaired Driving?

Objectives: The purpose of this investigation was to examine the relationship between impaired driving crashes and public beliefs and concerns about impaired driving across each of Maryland's twenty-four counties (including Baltimore City). It was hypothesized that residents of counties that experience higher impaired driving crashes would express more concerns about impaired driving and perceive more risks about driving impaired than residents of counties that have lower rates of impaired driving. Methods: Data for alcohol impaired driving crashes were obtained for the years 2004–2006. These data were compared to public opinion data that was obtained annually by random-digit-dial telephone surveys from 2004 to 2007. Results: Concerns about drunk driving as well as perceptions of the likelihood of being stopped by the police if one were to drive after having too much to drink were related to counties with higher serious impaired driving crash rates, as were perceptions that the police and the legal system were too lenient. Perceptions about the likelihood of being stopped by the police were higher in those counties with more impaired driving enforcement activity. Conclusion: Perceptions of concern appear to be shaped more by crash exposure than enforcement activity. Campaigns that address impaired driving prevention should substantially increase enforcement, strengthen the adjudication process of impaired drivers, and emphasize the potential seriousness of drinking-driving crashes in their promotional activities.

The potential role of physical activity on driving performance and safety among older adults

Abstract The elderly represent the fastest growing driving population. Older drivers have a high crash rate per distance traveled, a high risk of injury or death in traffic accidents, and are commonly found to be ‘at fault’ in crashes. This reality has focused more interest on issues associated with the fitness to drive and the safety of older drivers. Many older adults depend greatly on their personal vehicle for transportation and suffer a marked loss of quality of life when, as a consequence of no longer being able or permitted to drive, their mobility becomes significantly restricted. The reasons for the deterioration of driving performance that occur during the aging process are multi-factorial and a great deal of research has focused on the identification of those factors. Nevertheless, some studies incorporating training programs have tried, with some success, to improve the driving-related abilities of older drivers. It has been demonstrated that physical activity can promote several skills that are associated with driving performance in older drivers. Few studies, though, have conducted exercise interventions among older drivers intended to enhance their driving-related abilities and promote road safety. In this context, the purpose of this work consists of examining the perceptual, cognitive, health, and physical factors related to fitness to drive in older adults and identifying possible strategies that can enhance their driving-related abilities. Moreover, potential mechanisms underlying the relationship among physical activity, driving ability, and road safety are discussed.

Application of Bayesian Statistics to Identify Highway Sections with Atypically High Rates of Median-Crossing Crashes

This paper describes a Bayesian statistical technique for using crash records to estimate the frequency and rate of median-crossing crashes (MCCs) on each set of highway sections, in cases where MCCs are not explicitly identified in computerized crash records. This technique requires an analyst to review only a subset of hardcopy accident reports to produce a training sample, which is then used to identify computerized data associated (possibly imperfectly) with whether a crash was an MCC. This association can then be exploited to use larger sets of computerized records to increase statistical power over that provided by the training sample alone. This technique is applied to data from Minnesota's freeways and rural expressways. Estimates that allow highway sections to be ranked according to the estimated frequency or density of MCCs, or to the estimated MCC rate, are computed, and then the estimated frequency rankings are reported.

Aging Baby Boomers—A Blessing or Challenge for Driver Licensing Authorities

Introduction. In less than 5 years, the first wave of baby boomers will begin turning 65, with the last wave of boomers entering their senior years in January 2029. Currently, boomers make up a significant percentage of the population in Canada, the United States, and other developed countries. The baby boom generation has had a profound impact on our society over the last six decades, and this large cohort will continue to exert its influence for several decades to come. Central to this article is the rapid growth in the number of persons 65 years of age and older, beginning in 2011, with a corresponding increase in the number of older drivers. The demographic shift has important implications for licensing authorities, the regulatory bodies charged with licensing and ‘fitness to drive’ decisions. Objectives. The objectives of this paper are to summarize the published scientific literature on licensing policies and procedures currently in use for older drivers, discuss their limitations, and provide recommendations for meeting the upcoming challenges of an aging baby boomer population of drivers. Method. Online searches were conducted using the following databases: PsycINFO, MEDLINE, Scopus, and TRIS. Google and Google Scholar also were searched for scientific articles. References identified from database and online searches were examined for relevant articles. Results. A number of studies have investigated the utility of different licensing policies and procedures for identifying older drivers who may be at risk for impaired driving performance. Overall, results suggest that current policies and procedures are ineffective in identifying high-risk older drivers. The results also emphasize the need for a different approach for the identification of high risk older drivers by licensing agencies. Recommendations to assist with that goal are provided. Conclusions. The aging of the baby boomer population, combined with the projected high crash rates for this cohort of drivers as it moves through the senior years, underscores the need for cost-effective, accurate, and efficient methods for identifying and assessing the subgroup of older drivers whose driving has declined to an unsafe level. That subgroup consists of individuals with medical conditions (and treatments) affecting driving performance. The demographic shift has been a blessing for licensing authorities in that it has created awareness of the need for a reexamination of licensing policies and procedures designed to identify those older drivers who may no longer be safe to drive. If that awareness becomes translated into effective policies and procedures that appropriately target the medically at-risk/impaired older driver rather than the older driver per se, the result will be an increase in the safety and mobility of the older driving population and increased public safety overall. However, a continued focus on older drivers rather than medically at-risk drivers will result in a costly, ineffective, and overburdened system.

Survey explores teen driving behavior in Central Valley, Los Angeles high schools

Teenage drivers, particularly new drivers, have higher crash rates than adults. We surveyed 2,144 teenage drivers in California about their driving practices, factors influencing driving behavior, and views on driver education and resources. Teens wanted updated driver education courses and more behind-the-wheel training while learning to drive. They identified parents as their most important resource when learning to drive and also reported that parents were less likely to enforce the rule prohibiting driving with teen passengers than other driving rules. Teens described behavior by teen passengers that distracted them while driving. The findings indicate that new drivers benefit greatly from graduated driver licensing laws.

Spatial Analysis of Weather Crash Patterns

Spatial statistical techniques can be an effective tool for analyzing patterns and autocorrelation in crash data, especially weather-related crashes. Since weather is a geographic phenomenon, it tends to show distinct geographic patterns affecting certain locations more than others. Accordingly, “weather-related” crashes may also display similar distinct patterns or clustering. The objective of this research was to use spatial statistical techniques to identify significant patterns of weather-related crashes. Weather-related crashes, defined as those crashes which occurred in adverse weather conditions, were analyzed using the Getis-Ord Gi* (d) statistic. The statistic reveals spatial patterns for weather-related crashes which are clustered at different locations depending upon weather conditions (snow, rain, and fog). The results also show geographic areas (counties) of statistically significant high and low relative crash rates for each weather condition. Furthermore, the resulting patterns of crashes w...

The effects of mobile speed camera introduction on road traffic crashes and casualties in a rural county of England

ProblemThis study assesses the impact of crash and casualty numbers in correspondence to the introduction of mobile speed cameras in the rural county of Norfolk, England. MethodRoad traffic accident casualty and crash data were collected for two years before the introduction of cameras and two years subsequently. The casualties and crashes occurring at 29 camera sites were identified and separated from those occurring in the rest of the county. Trends in crashes and casualties, and their severity, were examined graphically and comparisons were made between before and after periods. The regression to the mean effect at individual sites was estimated. ResultsAfter the introduction of cameras, overall crashes declined by 1% and crashes involving fatalities or serious injuries declined by 9% on the roads without cameras. At the camera sites, crashes decreased by 19% and fatal and serious crashes by 44%. The reduction in total crashes was significantly greater than that expected from the effect of regression to the mean in 12 out of 20 sites tested. SummaryThe introduction of cameras appears to have resulted in real and measurable reductions in crash risk in this rural county. Impact on industryOur results suggest the deployment of mobile speed cameras is an effective tool for organizations wishing to reduce road traffic casualties in areas where high crash rates have been associated with excessive vehicle speeds.

Impact of Left-Turn Phasing on Older and Younger Drivers at High-Speed Signalized Intersections

The study reports on research that evaluated the impact of different types of left-turn phasing on older and younger drivers at high-speed signalized intersections. Using Poisson regression, the likelihood that a driver in a particular age group would be responsible for a left-turn crash under different types of phasing was evaluated. The induced exposure method was used to estimate exposure by age group. The variable of interest was left-turn crash rate for left-turning drivers who were responsible for circumstances contributing to the crash. Older drivers had higher crash rates than younger or middle-aged drivers for all types of phasing. Younger drivers had higher crash rates than middle-aged drivers for all types of phasing. All three age groups had the highest crash rate under protected/permitted and then permitted phasing within their respective age group.

Impact of federal compliance reviews of trucking companies in reducing highway truck crashes

Background The compliance review (CR) is a federal program monitoring motor carrier safety performance and regulatory compliance. This study sought to assess the impact of CRs on reviewed trucking companies in reducing truck crashes. Methods Data was from the Motor Carrier Management Information System. Study subjects were trucking companies established during 1990–1995, had at least one truck, and remained active until April 2004. Truck crash data of these companies was examined from 1996 to 2003. The crash rates in 2003 and annual percentage changes in number of crashes were computed. Analyses were stratified by company size, organization, operation classification, and safety rating. Results Companies that received CRs had a higher crash rate than never-reviewed companies. Reviewed companies experienced a 39–15% reduction in number of crashes in the year the CR was performed. The reduction in crashes was observed in all reviewed companies regardless of company size, operation classification, type of organization, or safety rating. The reduction in crashes was sustained for at least 7 years after CRs. Discussion The study results were controlled for the year in which CRs were performed, crash trend, and CR selection bias. However, further studies, especially a randomized prospective longitudinal study, are needed to overcome the limitations that are associated with an observation study.

Older drivers, medical condition, medical impairment and crash risk

New evidence has appeared to support the fact that the over-involvement of older drivers in traffic accidents disappears when the low mileage bias is taken into account. As a group, older drivers are as safe as or safer than other age groups, and only low mileage older drivers have a high crash rate. Furthermore, the role of the medical condition of older drivers in traffic accidents, as well as the fitness to drive evaluation, are objects of controversy. We examined all this with a cohort of 4316 drivers attending Medical Driving Test Centres for a mandatory fitness to drive evaluation. Our data shows that older drivers (≥75) have a lower crash rate. Medical conditions that impair fitness to drive, as a tendency, increased with advanced age and with lower mileage group. The multivariate analysis of variance showed that there is an effect ( p < 0.0001) of age-range and mileage on the annual crash rate per million kilometres driven, while a medical restriction (“fit to drive with restriction”) has no effect ( p > 0.05). Our data suggests that health status is not associated with increased crash risk for the low mileage group, although further studies are needed.

Family Physicians’ Attitudes and Practices Regarding Assessments of Medical Fitness to Drive in Older Persons

BackgroundHigher crash rates per mile driven in older drivers have focused attention on the assessment of older drivers.ObjectiveTo examine the attitudes and practices of family physicians regarding fitness-to-drive issues in older persons.DesignSurvey questionnaire.ParticipantsThe questionnaire was sent to 1,000 randomly selected Canadian family physicians. Four hundred sixty eligible physicians returned completed questionnaires.MeasurementsSelf-reported attitudes and practices towards driving assessments and the reporting of medically unsafe drivers.ResultsOver 45% of physicians are not confident in assessing driving fitness and do not consider themselves to be the most qualified professionals to do so. The majority (88.6%) feel that they would benefit from further education in this area. About 75% feel that reporting a patient as an unsafe driver places them in a conflict of interest and negatively impacts on the patient and the physician–patient relationship. Nevertheless, most (72.4%) agree that physicians should be legally responsible for reporting unsafe drivers to the licensing authorities. Physicians from provinces with mandatory versus discretionary reporting requirements are more likely to report unsafe drivers (odds ratio [OR], 2.78; 95% confidence interval [CI], 1.58 to 4.91), but less likely to perform driving assessments (OR, 0.58; 95% CI, 0.39 to 0.85). Most driving assessments take between 10 and 30 minutes, with much variability in the components included.ConclusionsFamily physicians lack confidence in performing driving assessments and note many negative consequences of reporting unsafe drivers. Education about assessing driving fitness and approaches that protect the physician–patient relationship when reporting occurs are needed.

Speed Difference and Its Impact on Traffic Safety of One Freeway in China

Although speed differential has long been recognized as a contributing factor to highway crashes, its relationship with crash rate has not been quantitatively established. An analysis of the crash data collected from the Jingjintang Expressway, one of the first freeways to be built in China, reveals a clear association between speed gap and crash rate. A difference in average operating speed between large and small vehicles of 10 to 15 km/h, reflecting a specific traffic composition, is associated with an unusually high crash rate. The speed differential problem is worse in developing countries because of the huge demand for freight transportation. Overloading is a common problem on highways. Heavily loaded trucks cannot reach the minimum freeway speed and so cause other vehicles to change lanes frequently; the situation consequently increases crash risks. Analysis results strongly suggest that managing the speed gap between large and small vehicles would be the most crucial step in combating the highway crash problem.