Jalil Shahi - Associate Professor, Iran University of Science and Technology
Mahmoud Ahmadinezhad۲, - Assistant Professor, Iran University of Science and Technology
Ali Naderan - Ph.D. Candidate, Iran University of Science and Technology

Aggregate crash prediction models (ACPM) attempt to relate the independent variables of interest aggregated at the zonal level to accidents using a mathematical equation. They predict number of crashes at each traffic analysis zone, and provide a basic tool to assess safety implications of large-scale transportation facilities at the network level for the long-range safety planning. This paper aims to critically review previous researches on the issue and evaluate the methodological approaches adopted to develop ACPM. A detailed analysis will be carried out on the mathematical formulation, goodness-of-fit tests, and the theory behind developing each model.

Mathematical models, Aggregate crash prediction, Poisson, Negative binomial