Fatality Risk of Intersection Crashes on Rural Undivided Highways in Alberta, Canada

Abstract

Intersections are recognized as the most hazardous locations on roads since conflict possibilities are high at intersections and often result in a high frequency of fatal crashes. A significant share of fatal crashes in Canada occur at intersections on rural undivided highways. Nevertheless, few studies have examined the factors contributing to the fatality risk of intersection crashes in Canada. In this study, a logistic regression model was applied to a sample of crash data at intersections on the rural undivided highways of Alberta, Canada, to investigate 18 factors and 71 variables. Of the significant factors, the major ones affecting the likelihood of fatality are the type of intersection, horizontal and vertical alignment of the highway at the intersection, signalization at the intersection, type of collision, impairment of drivers, and age of drivers involved in crashes. The fatality risk of intersection crashes tends to increase when crashes occur at offset intersections or at cross or T-intersections on horizontal curves. The likelihood of fatality tends to increase if the intersection is on a sag curve or at a constant grade. However, signalization at intersections tends to reduce the likelihood of fatality. Pedestrian-involved collisions, head-on collisions, right-angle collisions, and run-off-road collisions that involve hitting a fixed object and overturning of vehicles are associated with higher fatality risk. An intersection crash also tends to have a higher likelihood of fatality when it involves an older driver (>70 years) or impaired (by alcohol or drugs) or fatigued drivers.