Research On Safety Evaluation Of Lan Shang Expressway's Long And Steep Downgrade Section

With the rapid development of economy, Chinese expressway has realized leap growth. Recently, the construction of expressway is mainly concentrating in northwest, the expressway network has basically formed in eastern developed areas in our country. Based on the terrain characteristics of our northwestern areas, the expressways mostly traverse mountains,because of larger mountain area and complex topographical condition in our country,there exists some consecutive longitudinal routes inevitably. When vehicles traveling abovelong and steep downgrade sections, it is terribly easily appearing break failure phenomenondue to over-speed driving and long time breaking and leading to occurrence of accidents,which seriously affects roads traffic safety. So long and steep downgrade sections is multiple zone ofmajor malignant accidents.This paper bases on the collection and analysis of relevant information and documentation. First, analyze the road safety affected by road traffic dynamic system which composed by human, cars, roadway and traffic environment from micro-mechanism. Aim at consecutive longitudinal route, especially pointing out the significant affects that road environment to traffic safety. And further discuss the relationship of traffic safety with road alignment factors such as slope grade, slope length and radius. Next, aim at the practical situation of Lan Shang expressway's Long and steep downgrade sections,fall into common Long and steep downgrade sections and special Long and steep downgrade sections, from the plane alignment, vertical alignment, cross section and the line of sight and many other aspects of security analysis,anong special Long and steep downgrade sections include tunnel sections, bridge and tunnel connecting road sections, road slope. Through safely analysis, we can find out the place there do not safety or traffic safety problems of road and combined with the actual situation in the Lan Shang expressway, practical security measures put forward as to reduce the incidence of traffic accidents.