According to a study released by the Federal Motor Carrier Safety Administration (FMCSA) last week, drivers of large trucks and other vehicles involved in truck crashes are ten times more likely to be the cause of the crash than all other factors such as weather, road conditions or mechanical problems. Driver related causes accounted for 87% of truck-auto crashes, which beings safety experts a renewed focus on the driver to identify at-risk behavior and addressing this.

The Large Truck Crash Causation Study is the first nationwide look at all pre-crash factors. Previous data focused on specific crashes and individual causes.

“It confirms some things we’ve know in the insurance industry for a long time,” Jim York, Manager-Risk Engineering Transportation Team, Zurich Service Corp., told FleetOwner. “Many of the significant crashes are caused by at-risk driver behavior. The most important step in mitigating this is helping our insured clients to identify and manage at-risk driver behavior.”

According to the FMCSA study, in 42.6% of crashes involving a large truck and a car, and where the truck is at fault, poor decision-making on the part of the truck driver was the primary cause. The next most frequent cause (35.5%) were factors related to poor recognition, such as inattention, distractions and perception problems.

Interestingly, fatigue was almost twice as likely to be a factor for car drivers (14.7%) than for truck drivers (7.5%). Unfamiliarity with roadways was a factor almost twice as often (19.1%) for truck drivers as it was for automobile drivers (9.7%). Truckers were also more likely to drive too fast for conditions (15.2%) than were auto drivers (10.4%). Brake problems were a factor for trucks 27.0% of the time, but only 2.3% of the time for cars.

Interrupting traffic flow and failing to stop caused over 20% of the crashes, regardless of whether the driver of the truck or the car was at fault.

Overall, large trucks were responsible for 55% of the crashes in the study. In two-vehicle crashes involving a large truck and a passenger vehicle, passenger vehicles were responsible 56% of the time. This appears to contradict previous statistics cited by safety experts who generally agreed that automobile drivers were responsible for up to 75% of auto-truck crashes.

Many trucking safety experts arrived at this conclusion as “a result of looking at NHTSA FARS [fatality analysis reporting system] data,” Ian Grossman, FMCSA communications director told FleetOwner. “FMCSA and NHTSA had cautioned against this. [FARS] looks at police accident report identifying driver related factors. [But with this study] we look at all factors that increase the risk of having a crash. This is broader and more scientific as opposed to raw data collection.

“This suggests that critical reasons [for crashes] are more equally distributed [between truck and auto drivers] than earlier thought,” Grossman continued. “But regardless of whether it’s a car or truck, you see it is the driver behavior that’s causing the crashes."

Conducted with the assistance of the National Highway Traffic Safety Administration, the FMCSA study looked at a sample of crashes between April 2001 and December 2003 at 24 sites in 17 states, where each crash involved at least one large truck and resulted in at least one fatality or injury. A total of 967 crashes were analyzed, involving 1,127 large trucks, 959 non-truck motor vehicles, 251 fatalities, and 1,408 injuries.

“This study makes it clear that we need to spend more time addressing driver behavior, as well as making sure trucks and buses are fit for the road,” FMCSA Administrator Annette M. Sandberg said. “The multitude of data now available will allow us to analyze specific areas of behavior and work with our industry and safety partners to develop an agenda on driver safety that will improve commercial motor vehicle driver performance.”

FMCSA intends to examine driver factors such as use of prescription and over-the-counter drugs, speeding, fatigue, inattention, distractions, work environment, and unfamiliarity with the road.

“This was the most in-depth scientific study that looks at all the pieces that look at what caused the trucks-car accident,” said FMCSA’s Grossman. “We have a lot of safety programs that try different ways to prevent crashes. It’s a matter of how to prevent factors that are most likely to cause crashes and how to shift resources accordingly.”

To view the report, go to