Truck safety factors on urban arterials

Despite the high percentage of large truck trips on Interstate roadways, only 24% of fatal truck crashes occurred on these roadways. About 59% of large truck fatal crashes occurred on undivided highways that do not have controlled access and have signalized intersections. These statistics suggest that truck safety research should not only be aimed at Interstate driving conditions, but should also focus on improving truck safety for secondary roadways. One approach that can be used to better understand factors that impact truck safety on arterial roadways is through the use of accident prediction models. This paper describes the use of Poisson regression and negative binomial accident prediction models for truck accidents on an urban arterial with heavy truck volumes and a large number of signalized intersections. A model combining both signal and roadway segments showed good fit and demonstrates the ability to capture the impacts of both signal and roadway segments in one model.