Study On Traffic Safety Risk Assessment And Improvement Countermeasures Of Expressway In Hunan Province

With the rapid development of our country’s economy,both the mileage and traffic volume of expressway have increased significantly.At the same time,the safety situation of expressway traffic is becoming increasingly serious and frequent traffic accidents have become a serious threat to people’s life and property security."Active prevention" is the key to improving the level of expressway safety.At present,the study on expressway traffic safety in Hunan province are mainly concentrated on the traditional safety assessment and the cause analysis and emergency treatment of the accident,but the study on expressway infrastructure risk profile is less,which has obvious hysteresis.The risk assessment can not only quantitatively analyze the risk situation of expressway,but also provide the basis for the management and improvement of infrastructure in the traffic safety system.Through statistical analysis of the traffic accident data of nearly three years in Hunan province,the distribution characteristics of accident time,accident forms and accident causes were obtained.According to the traffic safety situation,the geographical,topographic and climatic characteristics,the influence of objective factors on expressway traffic safety is analyzed from five aspects:road alignment,road conditions,traffic safety facilities,traffic environment and roadside hazards.Based on the traffic accident statistics,the degree of traffic accidents induced by risk factors is objectively analyzed which lays the foundation for the selection of risk index and measurement of risk.Based on the fuzzy analytic hierarchy process(FAHP),an index system and a hierarchical structure model are established for the traffic safety risk assessment of expressway in Hunan province.The criteria and quantitative methods of each index are also determined.First of all,through the expert consultation method,analytic hierarchy process(AHP)and the YA-AHP software,the weight of each index are determined,which realize the combination of the subjective weight and the objective evaluation.Then,the secondary risk assessment is established on the basis of the fuzzy comprehensive evaluation method.Three methods(the mean of maximum method,the fuzzy distribution method and the weighted average method)are applied to deal with the fuzzy comprehensive vector in order to acquire the specific risk level,risk distribution and risk value.Finally,the evaluation model is applied on Tan Shao Expressway and the evaluation results are consistent with the actual situation,which can demonstrate its reasonability and feasibility.According to the results of risk assessment this paper puts forward some countermeasures to improve the traffic safety of expressway from different aspects.The study shows that the risk assessment model have great significance on identifying safety hazards,taking the initiative to prevent traffic accidents and improving road safety level.