The objective of this study was to examine a wide array of driver and situational factors that impact commercial motor vehicle (CMV) safety. The study evaluated the prevalence of these factors as well as their relationship to being involved in a crash or moving violation in a diverse sample of over 21,000 truck drivers. The goal was to identify and prioritize driver individual differences with respect to risk factors. Primarily, these risk factors consisted of personal factors, such as demographic characteristics, medical conditions, personal attitudes, and behavioral history. The study identified risk factors by linking the characteristics of individual drivers with their driving records, especially the occurrence or absence of crashes, during the duration of the study. The prospective study design afforded the opportunity to observe these drivers for up to 3 years using a combined dataset from carrier and national sources. This report documents the methods, data analyses, results, and conclusions involved in successfully conducting this study and evaluating the data.


This document is disseminated under the sponsorship of the U.S. Department of Transportation (USDOT) in the interest of information exchange. The U.S. Government assumes no liability for the use of the information contained in this document. The contents of this report reflect the views of the contractor, who is responsible for the accuracy of the data presented herein. The contents do not necessarily reflect the official policy of the USDOT. This report does not constitute a standard, specification, or regulation.

The U.S. Government does not endorse products or manufacturers named herein. Trademarks or manufacturers’ names appear in this report only because they are considered essential to the objective of this report.


The Federal Motor Carrier Safety Administration (FMCSA) provides high-quality information to serve Government, industry, and the public in a manner that promotes public understanding. Standards and policies are used to ensure and maximize the quality, objectivity, utility, and integrity of its information. FMCSA periodically reviews q