Study on Risk of Long-Steep Downgrade Sections of Expressways Based on a Fuzzy Hierarchy Comprehensive Evaluation

The long-steep downgrade sections of expressways are characterized by a large elevation difference, poor horizontal and vertical alignment, the easy failure brakes on trucks. They with high overall operation safety risk. It is necessary to strengthen research traffic risk evaluation. In order study risks parts expressways, fuzzy hierarchical comprehensive evaluation method used establish calculation model. First, an index system including target level, rule first-level level second-level established. qualitative quantitative indicators processed set value statistical linear standard method, respectively, so that all can be quantitatively evaluated together. Then, each indicator assigned score divided into five levels, ridge-shaped distribution constitute membership function for level. A structure model established analytic hierarchy process determine affiliation between upper lower relative weight also obtained. Finally, according relevance indicator, three-level constructed. obtained, probability corresponding calculated. Through Fuzhou Yinchuan Expressway in China, this shows conclusion obtained using consistent actual situation, which based operable.