Analysis Division - Federal Motor Carrier Safety Administration

The Large Truck Crash Causation Study (LTCCS) was jointly conducted with NHTSA to determine the causes and contributing factors involved in commercial motor vehicle (CMV) crashes. The agency investigated a national sample of fatal and injury crashes between April 2001 and December 2003 at 24 sites in 17 states. Each crash involved at least one large truck and resulted in at least one fatality or injury. The total sample of 967 crashes included 1,127 large trucks, 959 non-truck motor vehicles, 251 fatalities, and 1,408 injuries.

Up to 1,000 elements were collected from each crash and coded as either the Critical Event (the action by one vehicle that made the crash inevitable); the Critical Reason (the last failure on the part of the driver, the vehicle, or the roadway that explains why the critical event occurred); or Associated Factors (all of the conditions present at the time of the crash that may have played a role in why the crash occurred). None of these variables by themselves is considered the cause of the crash, but when analyzed can yield an understanding of crash causation and guide development of countermeasures.

FMCSA is conducting an ongoing comprehensive analysis of the LTCCS data and is specifically looking at driver factors such as legal drug use (both prescription and over-the-counter), traveling too fast for conditions (speed), fatigue, inattention (distractions), work environment, and unfamiliarity with the road. FMCSA is initiating new research areas on specific topics identified from the results of the LTCCS. These include: legal and illegal drug use; fatigue; vehicle condition with emphasis on brakes; speeding; inattention/distraction motor carrier pressure on drivers; traffic flow interruption such as congestion, other crashes, or traffic control devices; and unfamiliarity with roadway and vehicle driven. The LTTCS database is available to the public on the FMCSA website to encourage further analysis by all interested parties and to increase the total knowledge it can provide about large truck crash factors.