Evaluating safety of urban arterial roadways

This paper describes the development of accident prediction models for estimating the safety performance of urban arterial roadways in the Greater Vancouver Regional District, British Columbia, Canada. The traffic- and road-related variables that appear to underlie the occurrence of accidents are examined and models that explain the occurrence of accidents as a function of these variables are developed. To determine which variables have a significant effect on the safety of urban arterials, the study investigated a large number of models with different combinations of these variables. The investigation led to the conclusion that, among those variables examined, the ones that had a significant effect on accident occurrence were section length, traffic volume, unsignalized intersection density, driveway density, pedestrian crosswalk density, number of traffic lanes, type of median, and type of land use. The models were used to investigate the effect of the median type on accident occurrence. The study estimated that conversion from an undivided arterial to one with a raised-curb median could result, on average, in a 10% accident reduction.