Research On Safety Level Assessment Of Mountainous Highway Long Sloping Segment

Due to the complex topography of natural conditions and ecological constraints, there are often steep slope and ramp-long section of a long slope for highway in mountain areas. According to the crash statistics, long sloping segment related accidents account for 40% of mountain accidents. Long slope sections have witnessed high traffic accidents rate, and traffic safety situation is more severe than any other areas. However, though many researches have focused on the traffic safety improvement issue of long sloping segments for highway in mountain areas at present, there are still some problems unsolved, such as determining the priorities of the safety improvement segments, arranging funds, etc. Therefore, that safety level is classified for existing long slope segments could provide a theoretical basis for safety improvement of long sloping segments, so as to set a clearer purpose for such a project.In this paper, the data about long slope segments of mountainous highway is analyzed firstly and the safety of their long slope sections are addressed by statistics, including accident characteristics, the contributory factors on traffic safety etc, from the aspect of system.Then, on the basis of analyzing the main factors contributing to traffic accidents occurring at long slope segments in mountainous highway, from a systemic prospective, the evaluation indicator system is developed to describe the safety level of long slope segments of mountainous highway. By AHP approach, the judging matrix is established between the different layers. The consistency is checked by CI and RI values, and thus the weight is obtained.After describing the indicates and safety level division of long slope segments, quantitatively, whitening weight function is constructed by grey theory, and then fixed weigh grey cluster model is developed to understand the safety level of long slope segments, in which the evaluation process is provided and case example is used to check the effectiveness of this proposed model.Finally, this paper gives the traffic safety improvement measures from three aspects on the long-slope segments of the mountainous long slope segments of highway:preventing long slope segment of vehicle braking security initiatly, passive safety protection of brake failure, and driver & vehicle safety education and practice.