In late March, the Federal Motor Carrier Safety Administration (FMCSA) reported to Congress on the findings of its long-awaited Large Truck Crash Causation Study. The $18-million, four-year study examined the factors that contribute to truck crashes.

The study determined that driver actions and inactions were nearly ten times more likely to be the cause of a crash than non-driver factors like vehicle performance, weather or road conditions.

The study analyzed extensive data on 996 crashes that took place near 24 data collection locations in 17 states. To qualify, a crash had to involve at least one commercial vehicle with a GVW over 10,000 lb.

Researchers collected descriptive crash data about vehicles, drivers, roads and weather conditions. However, this study was different from previous efforts in that it was designed to look specifically at pre-collision events to gain greater understanding of the factors that lead to crashes. The goal was to be able to identify specific strategies that could be used to decrease truck crash frequency and severity.

The study examined both single vehicle (e.g., ran off roadway) and multiple vehicle (e.g., rear-end collision) events. Working backwards from the crash, researchers looked at the following factors:

  • Critical event: Action that put vehicle (s) on an unavoidable collision course.

  • Critical reason: Single or most predominant failure leading to the critical event.

  • Associated factors: Conditions or circumstances that led to the critical factor.

As an example, consider a work-zone collision where a passenger vehicle is rear-ended by a truck. The critical crash event is most likely the failure of the truck to slow down for stopped or slowed traffic. The critical reason for the event could be the failure of the driver to recognize the developing traffic conditions. Associated driver factors might include driving too fast for conditions, fatigue or inattention.

Using this approach, researchers determined that driver related items, such as recognition, decisions, and performance, were the critical reason for 87% of all crashes. For truck drivers, the most predominant associated factors included prescription/over-the-counter drug use, unfamiliarity with the road, inadequate surveillance and driving too fast for conditions. In crashes involving both a truck and a car, truck drivers were responsible for the critical reason 44% of the time.

This is the second study in six months linking driver behavior to crashes. Last December I reviewed the “ATRI High Risk Driver Study,” which found, among other things, that drivers convicted of improper or erratic lane change violations within the previous 12 months were 100% more likely to be involved in a crash in the following 12 months than drivers without such violations.

These studies make it impossible for us to ignore the importance of identifying and managing at-risk driver behavior. We must act now to improve our driver management and training systems.

The consequences of inaction could be significant. From a practical standpoint, plaintiffs' attorneys could point to a link between lax driver management systems and increased crash frequency. Such arguments will no doubt lead to significant jury awards.

I urge you to read and understand this latest report, which is available at

Jim York is the manager of Zurich Service Corp.'s Risk Engineering Transportation Team, based in Schaumburg, IL.