Research On Safety Design Standards And Methods For The Longitudinal Slope Of Continuouos Long Downgrade Section

Since China is a mountainous country, the design work for continuous long downgrade section exists inevitably in the process of highway construction. Data from a large amount of traffic accident materials in recent years show that continuous long downgrade section is accident-prone area. Therefore, it is of great significance to carry out a research on safety design standards and methods for the longitudinal slope of the continuous long section.Based on the typical continuous long downgrade section of road traffic and accident data analysis, this paper summarizes the traffic traits of continuous long downgrade road, and learns some characteristics and rules of traffic accidents, so as to reveal the relationship between continuous downhill road longitudinal slope control index and the accident rate, and it finds out that the accident prone section of long downhill section is mainly to blame the brake failure of trucks and speeding cars. To solve this problem, a relationship between vehicle brake failure(temperature) and road longitudinal cause of l slope design(index) is firstly established, based on the comparison of the temperature models of the truck brake drum. And then it proposes the standard of slope length control for different average longitudinal slope. In order to reduce the traffic accident incidence caused by vehicle brake failure, a new control criteria for the design of the longitudinal slope of the continuous long section of the downhill section is provided,which also improves the current "highway engineering technology standards" and "highway route design specification" by putting forward the average longitudinal slope of the freeway continuous long downgrade section and slope length control standards. Besides, combining with the evaluation theory and method of road alignment safety, the paper explores the approach and method of linear security assessment to improve the safety of longitudinal slope design of continuous long section slope section and uses it as the basis for continuous long downgrade road longitudinal slope design method of design process and general design steps. Finally, by making the safety evaluation of typical highway continuous long downgrade section and the comparison of accident data, it proves that the method and standard proposed in this paper are feasible and effective for preventing the accidents of continuous long downgrade road.This paper begins with the research on the inherent mechanism of traffic accident in the continuous long downhill section, and it combines evaluation method based on operating speed theory with evaluation method based on brake "hot recession" theory, to increase the reliability and applicability of the safety design method for the continuous long downgrade section. The results of research have certain directive significance and practical value for improvement of safety design standards and methods of continuous long downhill section, which not only reflects the "people-oriented, safety first" road safety design concept, but also plays a positive role in promoting the safety design of our future continuous long downgrade section.