Study of characteristics and evaluation of severity affecting factors associated with large-truck crashes

Large trucks form one of the important components of the surface transportation system in the United States as they carry a significant portion of the nation’s cargo. Statistics show that the total number of registered large trucks and the truck vehicle-miles traveled have both increased in the last 10 years. With this increase in numbers, the probability of trucks being involved in crashes also increases. This study identifies the characteristics and contributory causes of truck crashes, and the factors associated with increased severity of large-truck-crashes. By understanding these issues, more focused and effective countermeasures could be developed to mitigate both number and severity of truck-crashes. Various driver-, road-, environment- and vehicle- related characteristics and contributory causes were identified and analyzed using truck crash data from the state of Kansas. Driver-related contributory causes were found to be more common than any other type of contributory cause for the occurrence of truck-crashes. Failing to give time and attention, being too fast for existing conditions, and failing to yield right of way were the most dominant driver-related contributory causes, among many others. Through severity modeling, factors such as driver-related contributory causes, accident class, manner of collision, driver being under the influence of alcohol, truck maneuver, traffic control device, surface condition, being too fast for existing conditions, being trapped, damage to the truck, light conditions, etc. were found to be significantly related with increased severity of truck-crashes. Driver being trapped had the highest odds (82.81) of contributing to a more severe truck crash, followed by the collision resulting in damage to the truck, which had 3.05 times higher odds of increasing the severity of truck-crashes. Truck-driver under the influence of alcohol had 2.66 times higher odds of being involved in a more severe crash, among many other factors identified as important.