Analysis And Evaluation Of Operating Safety In Mountainous And Long Downhill Sections

Yunnan mountainous terrain is perplexed, on the low grade highways exist some continuous longitudinal slope sections. With the running speed the vehicle crosses through long downhill sections, because of the terrain conditions, in the presence of large longitudinal slope sections due to linear index and environmental factors are in the dynamic change of road, accident is easy to happen. These existing sections, caused great economic losses, seriously threat to the safety of human life; these sections causing serious traffic accidents frequently occurred in multiple segments, impact on road traffic safety.This paper fully collects low grade highway current situation, investigation and collection of traffic accidents in Yunnan on the basis of the data, to hand through the data and analysis of the mechanism of the accident and the place where the accident happened and the time rule. Drawing lessons from already existing accidents and road conditions such as alignment based on the index, analysis and summarys road alignment longitudinal slope indicators such as slope, slope length, radius of influence on traffic safety. On the other hand, according to the need of the subject, the field acquisition are two typical road downhill locations operating speed, the design of alignment index data. According to need of research, summing up the law of linear index, screening out the demand data, using statistical knowledge, combined with SPSS software using a linear regression model to the analysis of data fitting theory, to sort out the dependent variable (V85running speed) and independent variables (grade i, radius R, slope length1) in single factor fitting based on nonlinear fitting, are dependent variables in three under variable velocity model. Through the existing speed data and model predictions for velocity contrast, traffic safety evaluation to provide quantitative data to support it.Finally, in reference to existing traffic safety evaluation method on the basis of selection, reasonably evaluates index such as speed, the difference and the difference of adjacent slope, using cluster analysis method, the traffic safety level, to put forward the corresponding longitudinal slope of reasonable value and to find out the dangerous road, for the existence of hidden dangers sections to propose improvement measures.