The impact analysis of intersection sight distance on vehicle speed

Sight distance and vehicle speed are closely related to traffic safety, and good sight distance not only enable driver to judge the road traffic environment correctly, determine the correct driving behavior, but also determines effective operating time of the driving behavior. This paper made an in-depth analysis to intersection sight distance and turning characteristics, and carried on a statistical analysis to relationships among stopping distance, landscape static sight distance and the difference between them with vehicle speed, which took Mudanyuan Intersection of Haidian District in Beijing as an example and used mathematical models of the landscape static sight distance and the stopping distance. From the experiments we find that intersection sight distance have a strong correlation with vehicle velocity. Intersection static sight distance and sight distance difference have positive correlations with turning right vehicle velocity, while have negative correlations with direct vehicle velocity. Besides, it can be seen by combining the existing data that the greater static sight distance and sight distance difference are, the higher the maximum speed which is allowed and enable ensure the safety of traveling and turning right vehicle velocity are, but direct vehicle speed is lower, which has certain relations with driver psychology. Direct driving in the situation of smaller static sight distance and sight distance difference, drivers will be more anxious and then they are more inclined to speed up to avoid transportation conflicts and accidents; but if static sight distance and sight distance difference are greater, drivers will control accelerator and brake calmly, and the moving velocity will be lower.