Trucks more likely than cars to be the cause.

• Position: Severe Accidents

Trucks are responsible for 4,500 deaths per year in the U.S. Research by engineer and computer scientist Ben Hudson published in the International Journal of Injury Control and Safety Promotion details how trucks account for eight percent of U.S. highway traffic, yet are involved in 11% of fatal road crashes.

Previous research has revealed little other than that the severity of the crash bears a direct relation to abuse of drink and drugs, or inattention while driving. This study examined a sample of truck crashes over a five-year period in relation to different environmental factors, and used a model to determine crash severity outcomes. The authors considered 15 traffic factors ranging from condition of the driver, speed, vehicle characteristics, location, etc.

The main finding was that, overall, the percentage volume of trucks on the road was key in affecting severity of crash, even to the extent that lower traffic volume with a higher truck percentage heightens the risk of a fatal accident. An uptick of one percent truck volume results in a disproportionately higher increase in severe crash probability.

Speed was exposed as the other significant factor in determining severity of crashes, with severity escalating as speeds increase. Speeds above 45 mph were shown to double the...