Research on Influence Extention of Two-Lane Highway Intersections Based on Traffic Accident Database

Intersections are of great importance to highway network, and it is commonly thought that traffic accidents happen more at intersections than normal segments. Traffic conflicts and traffic flow changes always exist at some extention of intersections. It's extremely crucial to recognize the influence extention of intersections to the network, which can help to indentify the safety status of the intersections and to take corresponding countermeasures. The distribution of traffic accidents along the intersection center of each direction are analyzed based on the traffic accident database using traffic accident index. The distribution line of traffic accident index around intersections is like a Gaussian function, which is more higher at center. The line vividly shows that traffic accidents happen more at intersection centers, and decrease gradually as the space to intersection center increases, while the distribution of traffic accidents seems no change when the space is more than about 400 meters. 325 meters at each direction from intersection center are recognized as the intersection influence extention on two-lane highway after deeper analysis.