Risk Of Crash Involvement Research Articles

Substance use and driver fatality in Norway: An expanded case-control study.

Using alcohol or psychoactive drugs before driving a motor vehicle may increase the risk of crash involvement, injury, and death. This is better documented for alcohol than for drugs. The aim of this study was to expand a previous case-control study on substance use and driver fatality by doubling the number of cases and controls, and hence improve the statistical power and enable the analysis of combined substance use. We collected data on alcohol and drug use from all 1197 drivers of cars and vans who were fatally injured in road traffic crashes in Norway between 2005 and 2020 ('cases') by analyzing blood samples or reviewing other information on substance use. We also collected data on alcohol and drug use among 17,219 drivers in random road traffic ('controls') by analyzing oral fluid samples. Substance use was converted to dichotomous variables (no use/use). We used unconditional logistic regression to estimate adjusted odds ratios (aORs) with 95% confidence intervals (CIs) of driver fatality for mutually exclusive substance groups, adjusted for sex, age, geographic region, urban centrality class, and time interval of the week. Compared to no substance use, the aOR (95% CI) for driver fatality was for alcohol 91 (61-137), stimulants (primarily amphetamines) aOR 22 (9-56), benzodiazepines and z-hypnotics (BZDs) aOR 4.0 (2.7-5.9), tetrahydrocannabinol (THC) aOR 3.4 (1.7-6.7), and opioids aOR 1.4 (0.4-4.9). The aOR for any polysubstance use was 168 (96-297). The combinations of BZDs with stimulants or THC were associated with markedly higher aORs for driver fatality than the use of single substance groups. Alcohol and polysubstance use are the most important predictors of fatal injury, followed by stimulants.

The effectiveness and efficacy of driving interventions with ADHD: a Dutch perspective

The diagnosis of attention deficit hyperactivity disorder (ADHD) has been identified as a factor associated with an increased risk of involvement in car crashes. As a result, individuals in the Netherlands who are diagnosed with ADHD are mandated to undergo a psychiatric evaluation before obtaining their driving licence, optionally complemented with a driving test. Recent research has, however, demonstrated that 96% of individuals pass this procedure and can drive unrestrictedly, suggesting that current regulations have a limited impact and that a different regulatory approach may be warranted. This paper addresses three such potential interventions, exploring the scientific basis of implementing mandatory behavioural training programmes, the mandatory installation of driver monitoring systems, and temporary driving restrictions. To initiate this exploration, an analysis is made of the body of literature pointing towards a subpar driving performance in those with ADHD, accompanied by a discussion of the underlying symptoms and behaviours contributing to these findings. Furthermore, between- and within-individual factors affecting ADHD driving performance are reviewed. This examination illuminates a consistent pattern of substandard driving performances among those with ADHD, whereby the period shortly post-licensure stands out as a focal point for regulatory approaches. Following these results, the three potential driving interventions are reviewed to discern their impact on road safety when implemented specifically for drivers with ADHD. Corresponding studies suggest that all these interventions hold promise in improving driving performances, but the analysis is limited by the scarcity of long-term, ADHD-specific research. The paper concludes by discussing the feasibility of these ADHD-specific driving interventions, weighing their potential benefits, e.g., reduced crash rates, along with their associated costs, such as potential stigma and hindrance in societal integration and participation. Additionally, avenues for future research in these domains are outlined.

The Relative Risk of Alcohol-Involved Crashes as a Function of Time of Day.

Epidemiological research has repeatedly found that alcohol-impaired driving is associated with elevated risk of crash involvement in a dose-response fashion. Although experimental studies show that alcohol impairment of cognitive and psychomotor driving skills is exacerbated by sleep deprivation, there is less evidence that the combination of drowsiness and alcohol predicts actual motor vehicle crashes. We explored this by reanalyzing data from the National Highway Traffic Safety Administration Drug and Alcohol Crash Risk Study, constructing separate risk curves for daytime and nighttime hours. Controlling for driver demographics and driving exposure, and excluding other impairing drugs, we observed significantly greater risk of crash during the night versus the day at blood alcohol concentrations (BACs) between approximately .04 and .12 g/dl. Based on fitted point estimates, at .08 g/dl, the risk of crash at night was three times the risk of crash during the day. The association between BACs and crash risk was markedly different during daytime versus nighttime hours. Increased daytime risk was not observed until BACs exceeded the .08 g/dl per se legal limit. Results are interpreted as emphasizing the sedating role of alcohol. Implications are discussed.

1 Benefits of Speed of Processing Training in Older Adults

Objective:Physical, sensory, and cognitive function are all related to successful aging, quality of life, and independence in older age. Decline in cognitive function, in particular, can create difficulty in many Instrumental Activities of Daily Living such as driving and other aspects of everyday function. Loss of driving competence can subsequently lead to depression, isolation, loss of independence and reduced quality of life. Results from a large randomized controlled trial investigating the long-term impact of Speed of Processing Training will be presented demonstrating the impact of such training on cognitive and everyday function. Speed of Processing Training is an adaptive cognitive intervention administered on a computer that improves visual attention, and has been shown to enhance the connections needed for visual attention using task-driven and resting state fMRI.Participants and Methods:The ACTIVE clinical trial recruited a volunteer sample of 2,832 community dwelling older adults between the ages of 65 and 94 years at six different field sites in six different states. This study evaluated the impact of three cognitive interventions targeted at improving cognitive and everyday function which served as contract control conditions for each other. Participants were randomly assigned to speed of processing training, reasoning training, memory training, or a no-contact control group. Follow-up testing was collected in person for ten years, and at twenty years final archival data was collected from the Departments of Motor Vehicles at each of the six field sites, as well as the Medicare/Medicaid data across the twenty years since enrollment. Outcomes included measures of cognitive function, measures of IADL (including crash involvement and driving cessation), and secondary outcomes of mobility (falls, driving habits, life space), quality of life, mortality and health conditions (from Medicare Records).Results:Results will be presented with respect to everyday function including several longitudinal measures of mobility: number of miles driven per year and driving difficulty, rates of driving cessation, and crash involvement. Random effects modelling, cox proportional hazards, and rate ratios will be presented illustrating the positive impact of cognitive training on these outcome measures. In particular, Speed of Processing Training was found to sustain driving competence with respect to continued driving relative to other types of training, and to reduce the risk of crash involvement over ten years. Furthermore, decline in Speed of Processing was the only cognitive measure predictive of crash involvement longitudinally in the no-contact control group. Positive benefits were also observed for Health Related Quality of Life (HRQoL), and depression.Conclusions:The ACTIVE clinical trial, among other studies, has demonstrated that cognitive training can have long-term positive benefit on the everyday abilities, quality of life, and continued independence of older adults.

Associations between vision impairment and vision-related interventions on crash risk and driving cessation: systematic review and meta-analysis

ObjectivesTo systematically investigate the associations between vision impairment and risk of motor vehicle crash (MVC) involvement, and evaluate vision-related interventions to reduce MVCs.DesignMedline (Ovid), EMBASE and Global Health electronic databases...

National Analysis of Motor Vehicle Collision-Associated Mortality Among Opioid Users From 2010 to 2020: The Need for Effective Prevention Policies.

The purpose of this study is to evaluate the trends in the incidence of opioid-associated motor vehicle fatalities in the United States (US) over the past decade and identify geographic or demographic trends. We conducted a retrospective repeated cross-sectional study utilizing the CDC WONDER Multiple Cause of Death Database to gather data on opioid-associated motor vehicle fatalities from 2010 to 2020. The southern US experienced the highest percent increase in opioid-related fatalities from 2010 to 2020 (263.1%), followed by the Midwest (160.7%), the west (86.3%), and the northeast (10.0%). The use of opioids increases a driver's risk of motor vehicle crash involvement, especially amongst non-Hispanic White males between 25 and 55years of age who live in the southern states of the US. There is a need for augmented opioid-related policy concerning the potency and intake of prescription opioids to reduce motor vehicle fatalities.

Comment to: Does hearing loss affect the risk of involvement in a motor vehicle crash?

The Journal of Transport and Health recently published a paper (Dow et al., 2022) asking whether hearing loss affects the risk of involvement in a motor vehicle crash. The authors conclude that “the evidence does not support a relationship between hearing impairment and the risk of a motor vehicle crash.” This comment challenges this conclusion. It argues that the paper does not rely on the most informative findings in two of the four studies it bases its conclusion on. When the results of the four studies are formally synthesised by means of meta-analysis, it is found that the relative risk of crash involvement associated with hearing loss is 1.13 (CI 95: 1.05; 1.21).

Crash characteristics for classic/historic vehicles and comparisons to newer vehicles

Introduction: Older vehicles, commonly referred to as “classic,” “vintage,” or “historic” vehicles (CVH), share the roadways with newer vehicles. Older vehicles lacking safety systems likely come with an increased risk of fatality, however there is no study examining the typical conditions for crashes involving CVH. Method: This study utilized information from crashes occurring in 2012 to 2019 to estimate fatal crash rates for vehicles grouped by model year deciles. Data from crashes documented in the National Highway Traffic Safety Administration’s (NHTSA) FARS and GES/CRSS data sets were utilized to examine roadway, temporal, and crash types for passenger vehicles produced in 1970 or earlier (CVH). Results: These data show CVH crashes are rare (<1% of crashes), but carry a relative risk of fatality from 6.70 (95th CI: 5.44–8.26) for impacts with other vehicles, which was the most common crash, to 9.53 (7.28–12.47) for rollovers. Most crashes occurred in dry weather, typically during summer, in rural areas, most frequently on two lane roads, and in areas with speed limits between 30 and 55 mph. Factors associated with fatality for occupants in CVH included alcohol use, lack of seat belt use, and older age. Conclusions and Practical Applications: Crashes involving a CVH are a rare event but have catastrophic consequences when they do occur. Regulations that limit driving to daylight hours may lower the risk of crash involvement, and safety messaging to promote belt use and sober driving may also help. Additionally, as new “smart” vehicles are developed, engineers should keep in mind that older vehicles remain on the roadway. New driving technologies will need to safely interact with these older, less safe vehicles.

Convergent validity of vision based technology (VBT) among professional bus drivers

Introduction: Due to the relative rarity of crashes, researchers use traffic offenses, police records, public complaints, and In-Vehicle Data Recorder (IVDR) data as proxies for assessing crash risk. In this study, a unique IVDR system, called Vision-Based Technology [(VBT), (Mobileye Inc.)] was used to monitor perilous naturalistic driving events, such as insufficient distance from other vehicles and pedestrian or bicycle rider near-misses. The study aimed to test the convergent validity of VBT as an indicator of crash involvement risk. Methods: Data from 61 professional drivers working for a large bus company were analyzed (16 of 77 in the original data cohort were excluded for insufficient VBT data). Data included: recorded VBT data, objective data collected from official records (crash records provided by the bus company, and public complaints of reckless driving), self-report data regarding crash involvement, and police tickets. The correlation between VBT, objective and self-reported data was analyzed. Binary-logistic regression modeling (BLM) was used to calculate the odds ratio (OR) for participants involved in a car crash. Results: Correlations were found between the total VBT risk score and official crash records, public complaints, and self-reports of crash involvement. The BLM correctly classified 90% of those who were involved in a crash (sensitivity) and 60% of those who were “crash-free” (specificity). The VBT total risk score was the only significant contributing factor to crash risk, and for each point of increase, the odds of being involved in a crash increased by a factor of 1.55. Conclusions: It is the first study to provide empirical evidence validating the VBT as an indicator of crash involvement and driver safety among professional bus drivers. Practical Applications: VBT technology can provide researchers and clinicians a better understanding of bus drivers' risky driving behaviors- a valuable contribution to road safety interventions for this target group.

Adopting a Safe System Approach to Determine Safer Speed Limits: A Case Study from Iran

Speed management is one of the main dimensions of the Safe System Approach for reducing both the risk of crash involvement as well as injury severity. This study proposes a practical framework for setting safer speed limits on duplicated rural highways that has been applied to six pilot corridors (total carriageway length of approximately 1,250 km) in Iran. The safer speed limits determined from the proposed framework have been compared with the currently posted speed limits using several indicators and showed a considerable reduction in the total number of changes in speed limits while having very limited impact on reducing the mean travel speed and increase travel time along the study corridors. The study of the pilot corridors establishes that a clear approach and documented guidelines for setting speed limits provides a basis for quantifying engineering judgments about road hazards and determining more consistent speed limit values for similar conditions across Iran’s rural highway network, legitimising speed limit reductions aimed at saving lives.

Older Driver Safety: A Renewed Perspective in a Survey Study in Illinois, U.S.

Older adults (aged 65 or older) are at higher risk of involvement in motor vehicle crashes. Many studies have been conducted on older road users’ safety, but how older people’s driving behavior and demographic characteristics, and warnings of side effects of prescription medication, are associated with their crash risk has not been fully investigated. Aimed to address this knowledge gap, a mail survey of older drivers in Illinois, U.S. was conducted. Information on respondents’ driving behaviors, demographic characteristics, physical conditions, medication use, crash experience, etc. was gathered. Response distributions, odds ratios, and logistic regression models were employed to analyze the survey data. The results showed that most respondents kept a high level of mobility despite driving difficulty and medication use. Older drivers’ crash risk is mainly affected by external factors (driving exposure, alcohol consumption, and medication use) rather than their demographic characteristics and driving difficulty. Warnings from physicians on the side effects of prescription drugs had no significant effects on older drivers’ crash risk. Given the importance of mobility to older adults, the focus needs to be placed on providing a safe roadway system and safe driving advice for older drivers, particularly those who are on medication.

Development and validation of a questionnaire measuring knowledge, attitudes, and current practices of primary healthcare physicians regarding road injury prevention in older adults.

Older adults present high risk of involvement in road crashes. Preventive interventions conducted by their primary healthcare physicians (PHPC) could reduce this public health issue. The objective of this study was to design and validate a self-administered questionnaire that measures the knowledge, attitudes, and current practices (CP) of PHCP in Spain regarding the prevention of road injuries in older adults. One thousand eight hundred and ninety-seven PHCP completed a questionnaire piloted previously in an expert panel and two convenience samples of physicians. It comprised 78 items grouped in five sections and was mainly focused on exploring three constructs: knowledge, attitudes, and CP. Exploratory factor analysis was used to obtain evidence of internal structure validity. Reliability was assessed through Cronbach's α coefficient. Correlation coefficients for the scores constructed for each of the extracted factors were calculated to assess convergent and discriminant validity. Factor analysis extracted four factors each for the knowledge and attitudes constructs, and three factors for the CP construct, which explained more than 55% of the variance in each construct. Except for two factors of the knowledge construct regarding existing health problems associated to the risk of involvement in road crashes, the clustering pattern of all other items across the remaining nine factors was consistent and in agreement with previous knowledge. Cronbach's α values were greater than 0.7 for all constructs. Our questionnaire appears to be valid enough to assess the attitudes, CP, and medication-related knowledge of PHCP in Spain regarding the prevention of road injuries in older adults.

Road safety and heavy goods vehicle driving in LMICs: Qualitative evidence from Nepal

BackgroundHeavy goods vehicle drivers are an influential driving population in Nepal, with over 90% of goods in the country are transported by road. Due to the time spent on the road, drivers have long periods of exposure to the risk of crash involvement. The study explores the perceptions and experiences of heavy goods vehicle drivers and representatives from their professional association regarding road danger. MethodsWe conducted semi-structured interviews with fifteen heavy goods vehicle drivers regularly driving on the East-West highway of Makwanpur District, Nepal. A focus group was conducted with eleven members from a major transportation entrepreneur's association in Nepal. The focus group and interviews were audio-recorded, transcribed, translated, and analyzed using thematic analysis. ResultsFour themes were developed- assumptions of blame; perceptions of safety culture in the trucking industry; influence of road infrastructure; and behaviours of road users. The road and traffic environment, enforcement, and the safety culture in the heavy vehicle industry not only influenced the attitudes of the road users towards traffic safety but also legitimized and encouraged behaviours that affect safety. General and industry-related road safety improvements suggested by participants included: making provision for heavy good vehicles parking areas, separating the highway with a median strip, improving crash investigation capacity, conducting road safety awareness and training programs, strictly enforcing the speed limit and laws about driving under the influence of alcohol/drugs, and formulating strategies to create a safe, supportive working environment in the heavy vehicle industry. ConclusionHeavy goods vehicle drivers and members of the professional association can provide rich information regarding the barriers and facilitators of road risk in Nepal. Their perceptions and opinions can contribute to devising interventions at individual, societal, organizational, and governmental levels, and inform efforts to develop a positive safety culture within the heavy vehicle transport industry.

Modelling the relationship of driver license and offense history with fatal and serious injury (FSI) crash involvement

Introduction: Previous research has indicated that increases in traffic offenses are linked to increased crash involvement rates, making reductions in offending an appropriate measure for evaluating road safety interventions in the short-term. However, the extent to which traffic offending predicts fatal and serious injury (FSI) crash involvement risk is not well established, prompting this new Victorian (Australia) study. Method: A preliminary cluster analysis was performed to describe the offense data and assess FSI crash involvement risk for each cluster. While controlling demographic and licensing variables, the key traffic offenses that predict future FSI crash involvement were then identified. The large sample size allowed the use of machine learning methods such as random forests, gradient boosting, and Least Absolute Shrinkage and Selection Operator (LASSO) regression. This was done for the ‘all driver’ sample and five sometimes overlapping groups of drivers; the young, the elderly, and those with a motorcycle license, a heavy vehicle license endorsement and/or a history of license bans. Results: With the exception of the group of drivers who had a history of bans, offense history significantly improved the accuracy of models predicting future FSI crash involvement using demographic and licensing data, suggesting that traffic offenses may be an important factor to consider when analyzing FSI crash involvement risk and the effects of road safety countermeasures. Conclusions: The results are helpful for identifying driver groups to target with further road safety countermeasures, and for showing that machine learning methods have an important role to play in research of this nature. Practical Application: This research indicates with whom road safety interventions should particularly be applied. Changes to driver demerit policies to better target offenses related to FSI crash involvement and repeat traffic offenders, who are at greater risk of FSI crash involvement, are recommended.

A cognitive-behavioural intervention to reduce driving anger: Evaluation based on a mixed-method approach

Road anger is an increasing problem that does not only lead to discomfort but is also associated with aggressive driving and an increased risk of crash involvement. Based on a cognitive-behavioural approach, we developed and tested a short group intervention (90 min) that aimed at decreasing road anger among drivers. We used a before-after control group design, surveying people who did (EG) and who did not (CG) participate in the group intervention. The sample (n = 126) consisted of 80 men and 46 women with a mean age of 54 years (SD = 13). In addition, a sub-sample (n = 37) participated in a driving simulator study before and after the intervention. To enrich the survey- and simulator-based findings, we conducted a focus group discussion about post-intervention experiences in traffic. Comparisons of pre and post survey results showed that constructive expression as measured by a slightly revised sub-scale of the Driving Anger Expression Inventory (DAX-short), increased significantly for EG participants but not within the CG. In addition, the involvement in milder forms of road anger (e.g., yelling) decreased significantly in the EG but not in the CG. In the simulator study, we observed that EG participants decreased the extent of aggressive driving, commenting and gesturing – however, none of these differences were statistically significant. EG participants self-assessed the intervention overall positive and 44 % reported that they had changed their way of thinking or reacting in traffic. Overall, results indicate a positive effect of the cognitive-behavioural group intervention. Study limitations, possibilities to improve the intervention and different areas of application are discussed.

Cannabis and crash risk among older drivers

The purpose of this research was to reanalyze data collected from the National Highway Traffic Safety Administration’s Drug and Alcohol Crash Risk Study to investigate whether driving under the influence of cannabis (THC-positive) was associated with elevated crash risk for younger and older drivers. The data came from a case-control relative risk study collected from Virginia Beach, VA, over a 20-month period. Data collectors gathered driver information from the scene of vehicle crashes and, in some cases, from hospitals. Non-crash controls were sampled from the same locations, days, and times as crashes. Key data items included driver demographics and oral fluid and blood samples, which were assayed for licit and illicit drugs. We found no overall association between cannabis use and risk of crash involvement. However, when age and age2 were allowed to interact with THC, significant interaction effects emerged. THC was associated with increased risk of crash involvement for older drivers. Difference between THC-positive and sober drivers emerged as significant at age 64. The research underscores the value of examining drugged driving in the context of driver age. Age-related declines in neurocognitive and psychomotor functioning were not measured but might be important in explaining the results.

The impact of cognitive functioning on driving performance of older persons in comparison to younger age groups: A systematic review

Older drivers are at a severely higher risk for motor vehicle crash involvement. Due to the global aging of the population, this increased crash risk has a significant impact on society, as well as on an older individual’s quality of life. For this reason, there is a need for understanding how normal age-related changes in cognition and underlying brain dynamics impact driving performance to identify the functional and neurophysiological biomarkers that could be used to design strategies to preserve or improve safe driving behavior in older persons. This review provides an overview of the literature on age-related changes in cognitive functioning and brain dynamics that impact driving simulator performance of healthy persons. A systematic literature search spanning the last ten years was conducted, resulting in 22 eligible studies. Results indicated that various aspects of cognition, most importantly executive function, complex attention, and dual tasking, were associated with driving performance, irrespective of age. However, there was a distinct age-related decline in cognitive and driving performance. Older persons had a more variable, less consistent driving simulator performance, such as more variable speed adaptation or less consistent lane keeping behavior. Only a limited number of studies evaluated the underlying brain dynamics in driving performance. Therefore, future studies should focus on implementing neuroimaging techniques to further unravel the neural correlates of driving performance.

Cyclists injured in traffic crashes in Hong Kong: A call for action.

BackgroundPerceived as a minor transportation mode mainly for recreation, cycling and its related safety issues have not been treated as a citywide concern in Hong Kong and have thus received inadequate research efforts. Our study aimed to illuminate the safety challenges faced by cyclists in Hong Kong.MethodsWe examined the police crash records from 1998 to 2017 and developed a Bayesian Poisson state space model to evaluate the longitudinal change in traffic injuries to cyclists. We then used quasi-induced exposure to measure the annual relative risk of crash involvement for cycling. Based on an officially published travel characteristics survey, we further measured the risk of injury for cycling per minutes cycled.ResultsBetween 1998 and 2017, Hong Kong witnessed a more than twofold increase in the number of cyclist injuries, with an average annual increase rate of 5.18% (95% CI: 0.53%–12.77%). By 2017, cyclists were 2.21 (1.82–2.69) times more likely to be involved in traffic crashes than in 1998. Per 10 million minutes, the injury rates for cycling were 28.64 (27.43–29.70) and 42.54 (41.07–44.02) on weekdays during 2001–2003 and 2010–2012. After adjusting for sex and age groups, cyclists were 1.95 (1.43–2.61) times more likely to be injured in 2010–2012 than in 2001–2003. Per minutes traveled, cyclists also sustained significantly higher risks of fatality and injury than pedestrians, private car drivers and passengers, taxi passengers, public bus passengers, and minibus passengers. A comparison of Hong Kong with other regions suggests that Hong Kong is among the most dangerous areas for cycling in terms of fatality rate per minutes cycled.ConclusionsCyclist injuries have become a substantial public health burden in Hong Kong. A range of countermeasures with proven effectiveness should be promptly implemented to improve the safety of these vulnerable road users.

An investigation of the relationship between demographic variables, driving behaviour and crash involvement risk of bus drivers: a case study from Iran

The aim of this study was to model bus drivers’ crash involvement risk as a function of their demographic factors and driving behaviour. 177 bus drivers completed the bus driver risk index questionnaire. 19.2% of respondents had been involved in at least one at-fault crash during the past 3 years. In addition, age group and having a second job were found to affect the crash involvement rate. Smoker drivers reported significantly lower scores in patient driving and anxious driving factors. Results also indicated that vehicle ownership could improve hazard monitoring and thrill-seeking behaviours of bus drivers. Logistic regression suggested that drivers ≥55 years old are 5.4 times more likely to be involved in crashes, compared with drivers <35 years old. Model results also implied that the odds of crash involvement would decrease by 39% for each one-unit improvement in the scores of hazard monitoring behaviour. Implications are further discussed.

Contrasting Crash- and Non-Crash-Involved Riders: Analysis of Data from the Motorcycle Crash Causation Study

Motorcycle crashes and fatalities remain a significant public health problem as fatality rates have increased substantially as compared to other vehicle types in the United States. Analysis of causal factors for motorcycle crashes is often challenging given a lack of reliable traffic volume data and the fact that such crashes comprise a relatively small portion of all traffic crashes. Given these limitations, on-scene crash investigations represent an ideal setting through which to investigate the precipitating factors for motorcycle-involved crashes. This study examines motorcycle crash risk factors by employing data recently made available from the Federal Highway Administration Motorcycle Crash Causation Study (MCCS). The MCCS represents a comprehensive investigative effort to determine the causes of motorcycle crashes and involved the collection of in-depth data from 351 crashes, as well as the collection of comparison data from 702 paired control observations in Orange County, California. This dataset provides a unique opportunity to understand how the risk of crash involvement varies across different segments of the riding population. Logistic regression models are estimated to identify the rider and vehicle attributes associated with motorcycle crashes. The results of the study suggest that motorcycle crash risks are related to rider age, physical status, and educational attainment. In addition to such factors outside of the rider’s control, several modifiable risk factors, which arguably affect the riders’ proclivity to take risks, were also found to be significantly associated with motorcycle crash risk, including motorcycle type, helmet coverage, motorcycle ownership, speed, trip destination, and traffic violation history.