When this study was published by the International Journal of Injury Control and Safety Promotion, we found things in it that weren't all that surprising. For example, we knew that, when there are truck crashes, they cause significant losses in productivity, property, and personal injury. The study, which focused on trucks with a gross vehicle weight above of 10,000 pounds, also revealed some alarming facts about trucking.

This new study looked at a sample of truck crashes in Tennessee over a 5-year period and used a model to determine crash severity outcomes. They looked at 1134 crashes: 101 single-vehicle and 1033 multi-vehicle. The authors categorized crash severity as couched property damage only, non-incapacitating injury, incapacitating injury, and fatal. They also categorized factors affecting the crash, such as traffic, driver, vehicle, environmental, and geometric. The authors considered 15 traffic factors ranging from driver condition, speed, vehicle characteristics, location, and more.

Their findings: Trucks are responsible for 4500 deaths per year in the United States. And trucks account for 8 percent of U.S. highway traffic, yet are involved in 11 percent of fatal road crashes.

Also, the percentage volume of trucks on the road was the key factor that affected the severity of crash. They discovered that, even when traffic wasn't as heavy but there was a higher percentage of trucks, the risk of fatal accidents still increased. An increase of 1 percent of truck volume results in a disproportionately higher increase in the probability of a severe crash. The other major factor was speed. Not a huge surprise that the study showed the severity of crashes escalates as speeds increase. Speeds above 45 mph were shown to double the risk of a fatal crash.

Other interesting findings were that male drivers had more fatal crashes, due to "increasing likelihood of men to speed, act aggressively, or drive while impaired due to fatigue or substance abuse." Impaired drivers are almost seven times as likely to be involved in a fatal crash. The risk of a severe crash is far greater when the driver is affected by slower reaction times and poor judgment. And, of course, the longer the vehicle is, the higher the risk of a severe crash because the driver has a tougher time seeing the passenger-side view. The most significant environmental factor was weather. The worse the weather, the higher the risk of a severe crash. Snow can double the threat.

Source: Taylor & Francis, which published the article "Identifying the factors contributing to the severity of truck-involved crashes," International Journal of Injury Control and Safety Promotion