Safety Prediction Models of Freeway in Plain Terrain

摘要

This study analyzed the relationships between alignment elements and traffic accidents, traffic flow characteristics and traffic accidents, and environmental features and traffic accidents, which were based on the presumption that drivers on the freeway had better conditions for steering and had experience driving. The findings from the freeway Jing Jintang in plain terrain is that the ideal alignment design is not a main factor causing traffic accidents. There are strong and obvious correlations between traffic flow characteristics and traffic accidents and environmental features and traffic accidents. By means of nonlinear regression, the crash rates prediction models were constructed, the dependent variables are crash rates including three types which are: property damage only accident rate, casualty accident rate and the total accident rate. The independent variables are the characteristics of traffic flow and the environment. The three models can be used as management tools for traffic engineers to measure the safety of freeways.