Comprehensive Evaluation Of Highway Alignment Safety Based On Operation Speed

In recent years,the highway traffic accident has caused great personal injury and property damage in our country.Highway traffic safety situation is so pessimistic that in-depth study on the problem of road traffic safety should be taken without delay.According to the analysis of the factors of highway traffic safety,this paper choosed the speed index to study the highway alignment security.Firstly,this paper introduced several commonly used speed indexes briefly,and analysis the factors which influence the operation speed.Then made the argument for the necessity and feasibility of highway alignment safety evaluation based on operation speed.Then considering the environmental factors in the operation speed influence factors, climatic conditions will have a certain effect on the running speed,and ice and snow weather will be serious threat to safe driving.This paper then demonstrated the necessity of the study of weather conditions. Next,the influence of ice and snow weather conditions on the actual operation speed of the vehicle was analyzed from three aspects of pavement,driver and vehicle performance.Then this paper studied the two aspects of normal weather conditions and snow weather conditions.At last,this paper acquired the actual operation speed prediction model for the large truck on four typical road sections under two kinds of weather conditions like normal weather conditions and snow weather conditions.The next,as this paper made highway alignment safety comprehensive evaluation index selection principle and scope clear,four areas are determined,that was based on the coordination of the running speed,comfort,vision and based on the linear combination of coordination,from which this paper selected the highway alignment safety comprehensive evaluation index from.This paper also provided each index the formula and evaluation standard in the highway alignment safety comprehensive evaluation index system composed of four big indexes and twelve small indexes.Subsequently,after selecting the comprehensive evaluation method,this paper made it clear that the integrated evaluation method based on the fuzzy comprehensive evaluation method was selected.In terms of the weight of evaluation index,this paper used the clustering analysis method to improve the AHP method to determine the subjective weight,while used the entropy weight method to determine the objective weight.And then combined the subjective weight with the objective weight to acquire the combination weight.As to the membership degree of the evaluation index,the membership degree of the evaluation index was calculated by using the trapezoidal fuzzy distribution method.Based on all above,the fuzzy comprehensive evaluation model of the multi-level fuzzy comprehensive evaluation for highway alignment safety has been established.Finally,by using the design documents of Yan Pu high-speed and consider weather conditions of large trucks actual operation speed prediction model established in this paper chapter three,positive large truck operation speed prediction on Yan Pu high speed has been evaluated,and then the truck forward operation speed prediction values were obtained.Next,by using the highway alignment safety evaluation index system established in the fourth chapter,the calculation of the index value was evaluated according to the running speed forecast.On the basis of all above,this paper used the multi hierarchical clustering fuzzy comprehensive evaluation model to calculate the evaluation index weight and membership degree and fuzzy synthesis to get the comprehensive evaluation,and draw the conclusion of the evaluation.According to the conclusion of the evaluation,this paper also put forward some improvement measures and suggestions in accordance with those roads whose security level was bad.