Publication Information
The application of the generalized linear modeling approach to the development of a model relating unsignalized intersection traffic demands to accident frequency is described. Several techniques for assessing model fit have been described and any inherent limitations noted. The model was based on the product of the intersection traffic demands raised to a power. This model form was found to explain a large portion of the variability in accidents among intersections of similar geometry and traffic control. The analysis of accident data for 125 two-way stop controlled intersections supports the theory that the distribution of accident frequency for the group of similar intersections is gamma distributed. Knowledge of these distributions and their parametric values can be used to identify hazardous locations and the true effect of safety treatments on accident frequency.