California Partners for Advanced Transportation Technology

This report presents the findings of an examination of commercial motor vehicle crashes in California. Initially, a review of the basic descriptive statistics associated with truck-involved crashes in California was conducted; it covered the time period between January 1995 and December 2004 based on the Statewide Incident Tracking and Reporting System (SWITRS) data base, which contains information about every single motor vehicle accident in the state reported to a law enforcement agency. In addition to examinations of the entire population of truck-involved crashes in the state over the designated period, truck-involved crashes in Los Angeles County and the San Francisco Bay Area were also investigated. The next part of the report investigated the rates of truck accidents across California to determine the risk factors involved, including exposure to truck crashes, environmental conditions and demographic factors. The investigation involves modeling crashes as a function of these risk factors based on SWITRS data between 1998 and 2004.