Research On Traffic Safety Guarantee Method Of Expressway Tunnel Group

With the increasing number and mileage of highway tunnels,the proportion of tunnels in the total mileage of expressway is also gradually increasing,there are more and more continuous tunnels and adjacent tunnels,highway tunnel groups have been formed in some areas.Tunnel group sections are usually connected by multiple tunnels with shorter tunnel spacing,compared with other sections of the expressway,it has its own characteristics in terms of traffic composition,linear characteristics,driving behavior and environmental coordination.The traffic safety situation of the expressway tunnel group is very serious.The safety level and traffic capacity of the tunnel group directly affect and restrict the traffic capacity and service level of the entire expressway.Discriminating the traffic safety risks of the expressway tunnel group and proposing corresponding safeguard measures can ensure the smooth operation of the expressway tunnel group,improve the traffic safety level and service level,and promote the healthy and sustainable development of expressway traffic.This paper first introduces the definition of tunnel group,gives the recommended values of adjacent tunnels and continuous tunnel spacing combined with relevant research results and standard specifications;analyzes the characteristics of traffic environment and the characteristics of vehicle driving mode of highway tunnel group,the characteristics of the traffic environment are mainly considered from the aspects of visual characteristics,environmental illumination,noise,and air quality;analyzes the distribution characteristics of traffic accidents in expressway tunnels from five perspectives: accident time,accident space,accident pattern,accident models and accident weather;analyzes the influencing factors of tunnel group traffic safety from four aspects: driver,vehicle,road and environment,the driver factor mainly considers the driver’s visual characteristics,psychological characteristics and driving behavior,the vehicle factors are considered from the perspective of individual vehicle factors and group vehicles,the road factors mainly consider road alignment,road conditions,traffic engineering facilities,bridge and tunnel connections,the environmental factors consider both tunnel environmental factors such as ventilation and lighting,as well as adverse weather factors.Then selects discrimination indicators and builds an indicator system based on the analysis of traffic safety risk factors of expressway tunnel group,using subjective weighting method and objective weighting method to calculate the weight of each index,divide the expressway tunnel group traffic safety risk level into 5 levels and determine its magnitude interval or score interval,discriminating traffic safety risk of expressway tunnel group by using cloud model and matter element method;Finally,puts forward traffic safety guarantee measures from five aspects: traffic conditions,road conditions,traffic engineering facilities,tunnel environment and climate environment and establish a set of traffic safety guarantee measures,addresses various alternative schemes for different countermeasures,adopts the decision analysis method based on cumulative prospect theory,and combines the economic,timeliness,reliability and operability of each scheme to rank it,and provides decision support for managers to take guarantee measures.This paper studies the influencing factors,risk identification and guarantee scheme decision of expressway tunnel group traffic safety,however,the traffic safety guarantee of expressway tunnel group needs to consider many factors,the research in this paper still has some shortcomings,which need to be further analyzed and improved in the follow-up research.