Oregon's habitual traffic offender program: An evaluation of the effectiveness of license revocation

This report presents the results of a study of the effectiveness of license revocation for habitual offenders. Drivers whose licenses were revoked were compared with a similar group of drivers whose licenses were not revoked. All revoked drivers had significantly fewer nonmajor violations than did the control drivers. Revoked drivers who received the revocation notice (47%) also had significantly fewer accidents and major violations. Moreover, revoked drivers demonstrated a significant change in the pattern of violation types after revocation. It was concluded that: (a) revocation seems to be an effective way to deter habitual traffic offenders, because habitual offenders whose licenses are revoked have fewer traffic involvements than would be expected if they were not revoked; (b) license revocation would be more effective if the rate of delivery of the revocation notice was higher; and (c) even though many habitual offenders drive illegally after revocation, there is evidence that improved driving behavior, as well as reduced exposure, contributes to the effectiveness of the program.     

Problem driver remediation: a meta-analysis of the driver improvement literature

PROBLEM: Given the public safety risk posed by violation and crash repeaters and the substantial costs for state driver improvement programs, it is important that their effectiveness be scientifically demonstrated and that intervention programs are based on sound research findings. METHOD: Crash and traffic violation standardized effect sizes (d) representing 106 individual interventions were coded from 35 methodologically sound studies and analyzed using meta-analysis. RESULTS: Driver improvement intervention in general was associated with small but significant reductions in both crashes (dw = 0.03) and violations (dw = 0.06). Significant effects were found on both measures for warning letters, group meetings, individual hearings, and license suspense/revocation. Of the driver improvement interventions studied, license suspension/revocation was by far the most effective treatment for both crashes and violations (dw = 0.11 and 0.19). Since one of the objectives of license suspension/revocation is to eliminate driving for the period of suspension, it is possible that much or all of the effect is due to reduced exposure and/or more careful driving during the suspension interval. Results were mixed for other types of interventions, although distributing educational or informational material was not associated with any reductions. Interventions associated with violation reduction tended to also be associated with crash reduction, although the relationship was not very strong (r = .30). DISCUSSION: Although interpretation of the effect size estimates was complicated by almost ubiquitous heterogeneity, the results do suggest an overall positive impact of driver improvement interventions in general. IMPACT ON INDUSTRY: The results support the continued use of driver improvement interventions, chiefly warning letters, group meetings, individual hearings, and especially license suspension/revocation. The results also suggest that court-triggered traffic violator programs are less effective than interventions triggered by drivers license agencies.     

New Zealand drivers study: developing a methodology for conducting a follow-up study of newly licensed drivers

PROBLEM: In recent years, there has been a significant reduction in traffic crash injury among young people, but they continue to be overrepresented in the traffic crash statistics. To improve this situation, sound scientific evidence is needed to develop effective policies and programs. METHOD: The aim of the proposed study is to provide this evidence by examining early driving and driving-related experiences of newly licensed drivers as they progress through the learner-, restricted-, and full-license stages of the graduated licensing system and to determine the impact of these experiences on subsequent negative traffic-related outcomes (risky driving behavior, injury traffic crashes, noninjury traffic crashes, infringements, convictions). Given the size and complexity of the proposed study, a comprehensive pilot study was undertaken to determine the feasibility of conducting a New Zealand-wide cohort study of newly licensed drivers. RESULTS: This article describes the pilot study process and the methodology that has been developed for the New Zealand-wide study.     

Administrative license suspension: Does length of suspension matter?

Objective: Administrative license revocation (ALR) laws, which provide that the license of a driver with a blood alcohol concentration at or over the illegal limit is subject to an immediate suspension by the state department of motor vehicles, are an example of a traffic law in which the sanction rapidly follows the offense. The power of ALR laws has been attributed to how swiftly the sanction is applied, but does the length of suspension matter? Our objectives were to (a) determine the relationship of the ALR suspension length to the prevalence of drinking drivers relative to sober drivers in fatal crashes and (b) estimate the extent to which the relationship is associated to the general deterrent effect compared to the specific deterrent effect of the law.

Methods: Data comparing the impact of ALR law implementation and ALR law suspension periods were analyzed using structural equation modeling techniques on the ratio of drinking drivers to nondrinking drivers in fatal crashes from the Fatality Analysis Reporting System (FARS).

Results: States with an ALR law with a short suspension period (1–30 days) had a significantly lower drinking driver ratio than states with no ALR law. States with a suspension period of 91–180 days had significantly lower ratios than states with shorter suspension periods, while the three states with suspension lengths of 181 days or longer had significantly lower ratios than states with shorter suspension periods.

Discussion: The implementation of any ALR law was associated with a 13.1% decrease in the drinking/nondrinking driver fatal crash ratio but only a 1.8% decrease in the intoxicated/nonintoxicated fatal crash ratio. The ALR laws and suspension lengths had a significant general deterrent effect, but no specific deterrent effect.

Practical Implications: States might want to keep (or adopt) ALR laws for their general deterrent effects and pursue alternatives for specific deterrent effects. States with short ALR suspension periods should consider lengthening them to 91 days or longer.     

Do recommended driving limits affect teen-reported traffic violations and crashes during the first 12 months of independent driving?

OBJECTIVES: Motor vehicle crashes are highly elevated among newly licensed teenage drivers. Limits on high-risk driving conditions by driver licensing policies and parents can protect novice teens from negative driving outcomes, while they experience and driving proficiency. The purpose of this research was to evaluate the effects of strict parent-imposed driving limits on driving outcomes during the first year of licensure. METHODS: A sample of 3,743 Connecticut teens was recruited and randomized to the Checkpoints Program or comparison condition. Assessments conducted at baseline, licensure, 3-, 6-, and 12-months postlicensure included parent-imposed driving limits, traffic violations, and crashes. Bivariate and multivariate analyses were conducted to assess the effects of strict parent limits on traffic violations and crashes during the first year of licensure. RESULTS: Thirty percent of teens reported at least one traffic violation and 40% reported at least one crash. More strict parent-imposed limits at licensure, 3-, 6-, and 12-months postlicensure, were associated with fewer violations and crashes in multivariate analyses. Notably, adherence to recommended night curfew was consistently associated with fewer violations and crashes. CONCLUSIONS: The findings indicate that strict parent-imposed limits may protect novice teen drivers from negative driving outcomes.     

Effects of Dram Shop,Responsible Beverage Service Training,and State Alcohol Control Laws on Underage Drinking Driver Fatal Crash Ratios

Objectives: In this study, we aimed to determine whether three minimum legal drinking age 21 (MLDA-21) laws—dram shop liability, responsible beverage service (RBS) training, and state control of alcohol sales—have had an impact on underage drinking and driving fatal crashes using annual state-level data, and compared states with strong laws to those with weak laws to examine their effect on beer consumption and fatal crash ratios.

Methods: Using the Fatality Analysis Reporting System, we calculated the ratio of drinking to nondrinking drivers under age 21 involved in fatal crashes as our key outcome measure. We used structural equation modeling to evaluate the three MLDA-21 laws. We controlled for covariates known to impact fatal crashes including: 17 additional MLDA-21 laws; administrative license revocation; blood alcohol concentration limits of.08 and.10 for driving; seat belt laws; sobriety checkpoint frequency; unemployment rates; and vehicle miles traveled. Outcome variables, in addition to the fatal crash ratios of drinking to nondrinking drivers under age 21 included state per capita beer consumption.

Results: Dram shop liability laws were associated with a 2.4% total effect decrease (direct effects: β =.019, p =.018). Similarly, RBS training laws were associated with a 3.6% total effect decrease (direct effect: β =.048, p =.001) in the ratio of drinking to nondrinking drivers under age 21 involved in fatal crashes. There was a significant relationship between dram shop liability law strength and per capita beer consumption, F (4, 1528) = 24.32, p <.001, partial η² =.016, showing states with strong dram shop liability laws (Mean (M) = 1.276) averaging significantly lower per capita beer consumption than states with weak laws (M = 1.340).

Conclusions: Dram shop liability laws and RBS laws were both associated with significantly reduced per capita beer consumption and fatal crash ratios. In practical terms, this means that dram shop liability laws are currently associated with saving an estimated 64 lives in the 45 jurisdictions that currently have the law. If the remaining 6 states adopted the dram shop law, an additional 9 lives could potentially be saved annually. Similarly, RBS training laws are associated with saving an estimated 83 lives in the 37 jurisdictions that currently have the laws. If the remaining 14 states adopted these RBS training laws, we estimate that an additional 28 lives could potentially be saved.     

Traffic safety impacts of the Home Instruction/ Point Reduction Incentive (HI/PRI) program

The California Department of Motor Vehicles (DMV) implemented and evaluated a pilot driver improvement program involving the withholding (“masking”) from public inspection of one conviction from the driving record of qualifying drivers. To qualify for masking, the driver had to complete and return a mailed, self-administered test and remain free of traffic convictions and accidents for a period of 6 months after selection into the program. This Home Instruction/Point Reduction Incentive (HI/PRI) countermeasure was developed in two distinct versions: the Speed HI/PRI was designed for multiple violators of the 55 Maximum Speed Law (MSL), and the Negligent Operator (Neg-Op) HI/PRI was designed for drivers classified as negligent operators based on their traffic conviction record. Both HI/PRI countermeasures covered the safety and energy-saving advantages of 55-MSL compliance; the Neg-Op HI/PRI included general traffic safety material as well. The multiple 55-MSL violators were assigned at random to either the Speed HI/PRI or a no-contact comparison group. The negligent operators were assigned at random to one of four conditions: the Neg-Op HI/PRI, the existing DMV group educational meeting, a modified group meeting incorporating 55-MSL issues, or a no-contact comparison group. The Speed HI/ PRI and Neg-Op HI/PRI were each estimated to be cost-beneficial on the basis of accidents prevented. In addition, the Neg-Op HI/PRI had a larger estimated effect on accidents and lower cost than the group meeting countermeasures, which were also cost-beneficial. The coverage of 55-MSL issues in the group meeting did not appear to influence its effect in reducing either accidents or convictions. All of the countermeasures appeared to reduce subsequent convictions.     

Road traffic crashes among farm vehicle drivers in southern China: A cross-sectional survey

Objective: The objective of this study was to identify the prevalence and potential risk factors of farm vehicle–related road traffic crashes among farm vehicle drivers in southern China.

Methods: A cross-sectional study was used to interview 1,422 farm vehicle drivers in southern China. Farm vehicle–related road traffic crashes that occurred from December 2013 to November 2014 were investigated. Data on farm vehicle–related road traffic crashes and related factors were collected by face-to-face interviews.

Results: The prevalence of farm vehicle–related road traffic crashes among the investigated drivers was 7.2%. Farm vehicle–related road traffic crashes were significantly associated with self-reported vision problem (adjusted odds ratio [AOR] = 6.48, 95% confidence interval [CI], 3.86–10.87), self-reported sleep disorders (AOR = 10.03, 95% CI, 6.28–15.99), self-reported stress (AOR = 20.47, 95% CI, 9.96–42.08), reported history of crashes (AOR = 5.40, 95% CI, 3.47–8.42), reported history of drunk driving (AOR = 5.07, 95% CI, 2.97–8.65), and reported history of fatigued driving (AOR = 5.72, 95% CI, 3.73–8.78). The number of road traffic crashes was highest in the daytime and during harvest season. In over 96% of farm vehicle–related road traffic crashes, drivers were believed to be responsible for the crash. Major crash-causing factors included improper driving, careless driving, violating of traffic signals or signs, and being in the wrong lane.

Conclusion: Findings of this study suggest that farm vehicle–related road traffic crashes have become a burgeoning public health problem in China. Programs need to be developed to prevent farm vehicle–related road traffic crashes in this emerging country.     

Breath alcohol ignition interlock devices: controlling the recidivist

This study compares the recidivism rates of two groups of Illinois drivers who had their driver's licenses revoked for alcohol-impaired driving and who received restricted driving permits. Drivers in both groups had more than two driving under the influence (DUI) actions against their record within 5 years or were classed as level III alcohol dependents. Drivers in one group were required to install breath alcohol ignition interlock devices in their vehicles and drivers in the other group were not. The research found that drivers with the interlock were one-fifth as likely to be arrested for DUI during the 1 year the device was installed as the comparison group, which did not have the device. However, once the ignition interlock was removed, drivers in this group rapidly returned to DUI arrest rates similar to those in the comparison group. These findings echo previous literature. Additionally, the study showed that this voluntary program in Illinois reached only 16% of the drivers who met the requirements for installing the interlock device. Finally, this study found that individuals who were removed from the interlock program and returned to revoked status continued to drive. Within 3 years, approximately 50% of this latter group were involved in a crash or were arrested for DUI or with an invalid driver's license. Conclusions drawn from the study suggest that the breath alcohol ignition interlock device is effective in preventing continued driving while impaired. However, the large-scale effectiveness of the device is limited since most of the drivers eligible for the device do not have it installed. To have a significant impact, the interlock device must represent a better alternative to drivers whose licenses were suspended or revoked because of alcohol arrests compared to remaining on revoked status without having the device installed. Finally the research suggests that, given the rapid return to predevice recidivism, the devices should remain installed until drivers can demonstrate an extended period of being alcohol free.     

Breath alcohol ignition interlock devices: controlling the recidivist

This study compares the recidivism rates of two groups of Illinois drivers who had their driver's licenses revoked for alcohol-impaired driving and who received restricted driving permits. Drivers in both groups had more than two driving under the influence (DUI) actions against their record within 5 years or were classed as level III alcohol dependents. Drivers in one group were required to install breath alcohol ignition interlock devices in their vehicles and drivers in the other group were not. The research found that drivers with the interlock were one-fifth as likely to be arrested for DUI during the 1 year the device was installed as the comparison group, which did not have the device. However, once the ignition interlock was removed, drivers in this group rapidly returned to DUI arrest rates similar to those in the comparison group. These findings echo previous literature. Additionally, the study showed that this voluntary program in Illinois reached only 16% of the drivers who met the requirements for installing the interlock device. Finally, this study found that individuals who were removed from the interlock program and returned to revoked status continued to drive. Within 3 years, approximately 50% of this latter group were involved in a crash or were arrested for DUI or with an invalid driver's license. Conclusions drawn from the study suggest that the breath alcohol ignition interlock device is effective in preventing continued driving while impaired. However, the large-scale effectiveness of the device is limited since most of the drivers eligible for the device do not have it installed. To have a significant impact, the interlock device must represent a better alternative to drivers whose licenses were suspended or revoked because of alcohol arrests compared to remaining on revoked status without having the device installed. Finally the research suggests that, given the rapid return to predevice recidivism, the devices should remain installed until drivers can demonstrate an extended period of being alcohol free.     

A data mining approach to deriving safety policy implications for taxi drivers

Introduction: Traffic safety issues associated with taxis are important because the frequency of taxi crashes is significantly higher than that of other vehicle types. The purpose of this study is to derive safety implications to be used for developing policies to enhance taxi safety based on analyzing intrinsic characteristics underlying the cause of traffic accidents. Method: An in-depth questionnaire survey was conducted to collect a set of useful data representing the intrinsic characteristics. A total of 781 corporate taxi drivers participated in the survey in Korea. The proposed analysis methodology consists of two-stage data mining techniques, including a random forest method, with data that represents the working condition and welfare environment of taxi drivers. In the first stage, the drivers’ intrinsic characteristics were derived to classify four types of taxi drivers: unspecified normal, work-life balanced, overstressed, and work-oriented. Next, priority was determined for classifying high-risk taxi drivers based on factors derived from the first analysis. Results: The derived policies can be categorized into three groups: ‘the development of new policies,’ ‘the improvement of existing policies,’ and ‘the elimination of negative factors.’ Establishing a driving capability evaluation system for elderly drivers, developing mental health management programs for taxi drivers, and inspecting the taxi's internal conditions were proposed as new policies. Improving the driver's wage system, supporting the improvement of rest facilities, and supporting the installation of security devices for protecting taxi drivers are methods for improving existing policies to reinforce the traffic safety of taxi drivers. Last, restricting overtime work for taxi drivers was proposed as a policy to eliminate negative factors for improving taxi traffic safety. Practical Applications: It is expected that by devising effective policies using the policy implications suggested in this study, taxi traffic accidents can be prevented and the quality of life of taxi drivers can be improved.     

Risk factors for the severity of injury incurred in crashes involving on-duty police cars

Objective: This article explores the risk factors associated with police cars on routine patrol and/or on an emergency run and their effects on the severity of injuries in crashes.

Methods: The binary probit model is used to examine the effects of important factors on the risk of injuries sustained in crashes involving on-duty police cars.

Results: Several factors significantly increase the probability of crashes that cause severe injuries. Among those causes are police officers who drive at excessive speeds, traffic violations during emergency responses or pursuits, and driving during the evening (6 to 12 p.m.) or in rainy weather. Findings also indicate some potential issues associated with an increase in the probability of crashes that cause injuries. Younger police drivers were found to be more likely to be involved in crashes causing injuries than middle-aged drivers were. Distracted driving by on-duty police officers as well as civilian drivers who did not pull over to let a police car pass in emergency situations also caused serious crashes.

Conclusions: Police cars are exempted from certain traffic laws under emergency circumstances. However, to reduce the probability of being involved in a crash resulting in severe injuries, officers are still obligated to drive safely and follow safety procedures when responding to emergencies or pursuing a car. Enhancement of training techniques for emergency situations or driving in pursuit of an offender and following the safety procedures are essential for safety in driving during an emergency run by police.     

基于事故深度调查的城市交通事故特征分析

为探索适合我国的事故数据深度采集标准,并分析城市道路交通事故特征及致因,基于《道路交通事故深度调查信息采集表》(简称采集表),调查人员随交警赴事故现场随机详细调查87起城市道路交通事故。借鉴"Haddon Matrix"思想建立致因分析矩阵系统,分析事故的致因。发现采集表对事故地点、事故形态及原因项分类更加具体、明确,女性驾驶员的事故发生率略低于男性驾驶员,驾驶员年龄超过60岁后,发生事故的危险性显著提高,"交叉口影响区"事故50%由变更车道引起,非机动车驾驶员未戴安全头盔是造成严重伤害的重要原因。     

Aggressive behavior while driving as predictor of self-reported car crashes

PROBLEM: In Greece, there is a lack of scientific evidence on the relationship between aggressive behavior while driving and young drivers' involvement in car crashes; this study examined this potential relationship. METHODS: The randomly selected samples of 356 young drivers (18-24 years old) were interviewed through a questionnaire of self-reported car crash involvement, which mainly focused on their behavior on the road and the number of car crashes in which they had been involved. RESULTS: The statistical methods used were principal components analysis (PCA) and multiple regression analysis. Two factors relevant to aggressive driving emerged: (a) driving violations and (b) irritability while driving. The multivariate model suggested that driving just for fun (joyriding) and irritability were predictors of young drivers' involvement in car crashes. It was found that younger age was negatively associated with young drivers' involvement in car crashes. IMPACT ON GOVERNMENT AND INDUSTRY: The findings of this study can contribute in the formation of public policies aiming to prevent young drivers' car crashes. These findings can also be the starting point of some health promotion interventions trying to reduce car crashes and casualties on the road. Finally, the insurance companies may be interested in applying these findings into their field of interest.     

Prediction of vehicle crashes by drivers' characteristics and past traffic violations in Korea using a zero-inflated negative binomial model

Aims: Traffic safety is a significant public health challenge, and vehicle crashes account for the majority of injuries. This study aims to identify whether drivers' characteristics and past traffic violations may predict vehicle crashes in Korea.

Methods: A total of 500,000 drivers were randomly selected from the 11.6 million driver records of the Ministry of Land, Transport and Maritime Affairs in Korea. Records of traffic crashes were obtained from the archives of the Korea Insurance Development Institute. After matching the past violation history for the period 2004–2005 with the number of crashes in year 2006, a total of 488,139 observations were used for the analysis. Zero-inflated negative binomial model was used to determine the incident risk ratio (IRR) of vehicle crashes by past violations of individual drivers. The included covariates were driver's age, gender, district of residence, vehicle choice, and driving experience.

Results: Drivers violating (1) a hit-and-run or drunk driving regulation at least once and (2) a signal, central line, or speed regulation more than once had a higher risk of a vehicle crash with respective IRRs of 1.06 and 1.15. Furthermore, female gender, a younger age, fewer years of driving experience, and middle-sized vehicles were all significantly associated with a higher likelihood of vehicle crashes.

Conclusions: Drivers' demographic characteristics and past traffic violations could predict vehicle crashes in Korea. Greater resources should be assigned to the provision of traffic safety education programs for the high-risk driver groups.     

Implementation of Washington State's zero tolerance law: patterns of arrests, dispositions, and recidivism

OBJECTIVES: Zero tolerance (ZT) laws have been effective in reducing alcohol-related crashes among underage drivers. However, enforcement in some states has not been rigorous, and ZT offenses may not be viewed as serious offenses. On July 1, 1994, the state of Washington implemented a ZT law that allowed police to request a test for alcohol on suspicion of either a ZT or driving-under-the-influence (DUI) offense. The present study examined effects of the ZT law on arrests and case dispositions among underage offenders as a function of blood alcohol concentration (BAC) and post-law patterns of recidivism. METHODS: Times-series analyses examined the effects of the ZT law on trends in arrests of underage drivers between 1991 and 1999. Based on arrest records matched with driver's license records, the effects of the law on dispositions of alcohol-related offenses among underage drivers were examined, and rates of recidivism among underage offenders were examined for the period following the ZT law. RESULTS: There was a substantial increase in arrests of underage drivers beginning immediately after implementation of the ZT law, especially among drivers with low BACs. The types of court or administrative dispositions received by underage offenders changed markedly after the ZT law was implemented. Underage offenders with lower BACs became far more likely to receive alcohol-related convictions and/or license suspensions. However, the percentage of underage offenders with higher BACs receiving DUI convictions declined as some of these offenders received the lesser ZT disposition. After the ZT law, underage offenders with BACs of 0.10 g/dL or higher were more likely to recidivate than those with lower BACs, but appreciable proportions of drivers were re-arrested for another alcohol offense, whatever the BAC and however they were penalized. CONCLUSIONS: Implementation of Washington's law indicates that a ZT law can increase the likelihood that an underage person will be sanctioned for drinking and driving. However, recidivism remains an issue as more than one in four underage drivers arrested with low BACs subsequently were re-arrested.     

Analyses of rear-end crashes based on classification tree models

OBJECTIVE: Signalized intersections are accident-prone areas especially for rear-end crashes due to the fact that the diversity of the braking behaviors of drivers increases during the signal change. The objective of this article is to improve knowledge of the relationship between rear-end crashes occurring at signalized intersections and a series of potential traffic risk factors classified by driver characteristics, environments, and vehicle types. METHODS: Based on the 2001 Florida crash database, the classification tree method and Quasi-induced exposure concept were used to perform the statistical analysis. Two binary classification tree models were developed in this study. One was used for the crash comparison between rear-end and non-rear-end to identify those specific trends of the rear-end crashes. The other was constructed for the comparison between striking vehicles/drivers (at-fault) and struck vehicles/drivers (not-at-fault) to find more complex crash pattern associated with the traffic attributes of driver, vehicle, and environment. RESULTS: The modeling results showed that the rear-end crashes are over-presented in the higher speed limits (45-55 mph); the rear-end crash propensity for daytime is apparently larger than nighttime; and the reduction of braking capacity due to wet and slippery road surface conditions would definitely contribute to rear-end crashes, especially at intersections with higher speed limits. The tree model segmented drivers into four homogeneous age groups: < 21 years, 21-31 years, 32-75 years, and > 75 years. The youngest driver group shows the largest crash propensity; in the 21-31 age group, the male drivers are over-involved in rear-end crashes under adverse weather conditions and the 32-75 years drivers driving large size vehicles have a larger crash propensity compared to those driving passenger vehicles. CONCLUSIONS: Combined with the quasi-induced exposure concept, the classification tree method is a proper statistical tool for traffic-safety analysis to investigate crash propensity. Compared to the logistic regression models, tree models have advantages for handling continuous independent variables and easily explaining the complex interaction effect with more than two independent variables. This research recommended that at signalized intersections with higher speed limits, reducing the speed limit to 40 mph efficiently contribute to a lower accident rate. Drivers involved in alcohol use may increase not only rear-end crash risk but also the driver injury severity. Education and enforcement countermeasures should focus on the driver group younger than 21 years. Further studies are suggested to compare crash risk distributions of the driver age for other main crash types to seek corresponding traffic countermeasures.     

Antecedents of fatigue, close calls, and crashes among commercial motor-vehicle drivers

PROBLEM: Minimizing driver fatigue among commercial motor-vehicle (CMV) drivers is a major safety issue in the United States. This study examines the effects of potentially fatigue-inducing factors inherent in truck driving work and company safety management in explaining: (a) drivers driving while fatigued, (b) the frequency of close calls due to fatigue, and (c) actual crashes among CMV drivers. METHOD: Data for this study are derived from a survey of CMV drivers in 116 trucking firms, with all data being driver-reported. The relative roles of fatigue-inducing factors and safety management practices in explaining variation in fatigue, close calls, and crashes are reported, along with the roles of fatigue in affecting close calls and crashes via hierarchical regression. RESULTS: Findings indicated that fatigue-inducing factors inherent in driving work and safety practices accounted for appreciable variation in driving fatigued (R(2) =.42) and close calls (R(2) =.35), but not crash involvement. Driving while fatigued also accounted for incremental increases in the amount of variation in close calls, after consideration of inherent factors and safety practices. IMPACT ON INDUSTRY: Findings indicate that safety practices (e.g., establishment of a strong safety culture, dispatcher scheduling practices, company assistance with fatiguing behaviors such as loading and unloading) have considerable potential to offset fatigue-inducing factors associated with truck driving work.