Modeling Multiple -Vehicle Property Damage Collisions in Urban Signalized Intersections

Development of disaggregate models for estimating different property damage collision type frequencies in urban intersections has rarely been studied, particularly in iran. it seems that very little research work has been implemented for studying the factors affecting the collision type frequency at intersections. the main objective of this paper is to develop suitable statistical models to predict types of property damage accident frequencies at signalized intersections approaches in the city of mashhad, iran, based on geometric, traffic and regulatory control characteristics. three neg-ative binomial models are estimated for collisions occurred in four-leg signalized intersections in the city of mashhad and their results were compared. these models are total, rear-end and right angel collision models. the goodness of fit was assessed by statistic tests. the incidence rate ratio is used to assess the effectiveness of independent variables on frequency of property damage collision. validation of models was controlled using paired samples t-test method. modeling collision types showed a strong relationship between frequency of property damage collision types and independent variables such as road geometry, the type of control system and traffic characteristics. results revealed that seven of independent variables considerably affect the safety of signalized intersections