The Analysis On Traffic Safety About Long Steep Slope Of Mountain Highway

With the implementation of "7918" national highway net and the western development strategy, the expressway in mountain area ushered in the new construction peak. Be influenced by topography, the long steep slope is inevitable during the alignment design of expressway in mountain area. However, continuous long steep slope is of great disservice to traffic safety, which makes the long steep slope becomes the Accident-prone area and is also called "black spot" of expressway. Therefore, studies on the safety factors of the long steep slope are very important to improve driving safety and service level of the expressway in mountain area.In this paper, the methods of Highway Safety Audit and Principal Componentv -Cluster Analysis were used to analyze the traffic safety of long steep slope section. A series of valuable achievements were got. First, the factors that influence the traffic safety of long steep slope at expressway in mountain area include humans, cars, roadways, traffic environment and so on, the inharmonious of which causes road traffic accidents. Second, excessively using the limit value of specifications and standards in route design could decrease the driving safety, and increase potential danger. Third, combining the design conformance inspection and the speed coordination analysis is an effective method to evaluate the traffic safety of long steep slope. Fourth, the loss of traffic accident could be reflected by the safety audit index F1 of principal component-Cluster Analysis, which can further represent the situation of traffic safety.