Analysis and Modeling of Safety Based on Expressway Traffic Flow State

It is thought volume and speed of traffic flow have great influence on traffic safety in many researches. Besides, considering operating environment of expressways of PRC (People's Republic of China), the paper believes proportion of heavy vehicle is also an important influencing factor. Based on the data of Jiliao Expressway, the paper respectively analyzes the relationship between accident rate and signal characteristic parameter traffic volume per hour, average speed, coefficient of speed variation and proportion of heavy vehicle. Then, taking the four characteristic parameters as independent variables, the paper establishes accident rate prediction model by regression analysis and verifies the model. The model can be used to evaluate traffic safety of expressways.