Study On Traffic Safety Evaluation Of Urban Expressway Tunnel Group

With the rapid development of China’s society and economy,the process of urbanization continues to advance,and the application of expressway tunnel groups has greatly facilitated traffic travel,but also brought new challenges to the traffic safety of the city.Tunnel group refers to the general term of two or more tunnels spaced at a certain distance on the highway section,which has the characteristics of many safety influencing factors,easy to induce secondary accidents,and high emergency rescue requirements.The southern expressway tunnel group in Yangzhou is composed of 5 continuous tunnels,and the length of each tunnel is different,the plane linear shape is large,and the speed limit standard is different.Since the tunnel group is an important part of the city’s east-west traffic artery,it is of important reference value and practical significance to carry out traffic safety evaluation research on it to reduce accident hazards and improve the level of safety management.In this paper,the influencing factors of traffic safety are first analyzed and the investigation plan is formulated for the tunnel group of yangzhou southern expressway from the four aspects of traffic operation characteristics,tunnel infrastructure,traffic safety facilities,and climate environment.The combination of surveillance video and UAV aerial photography is used to obtain relevant traffic operation data and analyze the traffic characteristics of the tunnel group.Secondly,based on the structural characteristics,traffic operation characteristics and traffic management measures of the Yangzhou Southern Expressway Tunnel Group,the traffic safety evaluation indicators were selected for 5 tunnels and 4 tunnel connection sections,and the weight of the evaluation indicators was determined by using the analytic hierarchy method,and 5 evaluation levels were divided.Finally,a traffic safety evaluation model of the tunnel group is constructed by fuzzy comprehensive evaluation method,and the example of the tunnel group of the Southern Expressway in Yangzhou is verified and analyzed.The results show that the average speed,the line of sight of the driving,the proportion of the length of the curve section,the line shape of the tunnel inlet and outlet,the maximum longitudinal slope value,and the road surface slip resistance are the key factors affecting the traffic safety of the expressway tunnel group.Interwoven flow ratio,sink-out ratio,number of lane changes by 100 vehicles,speed difference,linear continuity,road surface slip resistance,and drainage are the key factors affecting the traffic operation safety of the interwoven area of the expressway tunnel.At the same time,this paper considers the combined situations under different traffic conditions,analyzes the sensitivity of the evaluation model,and proposes corresponding traffic management countermeasures.Based on the analysis of the influencing factors of the traffic safety of the tunnel group and the analysis of traffic characteristics,this paper constructs the traffic safety evaluation index system and evaluation model of the urban expressway tunnel group,and the research results have certain theoretical significance and guiding effect on the traffic safety management of the urban expressway tunnel group in China.