Study On Key Problems Of Freeway Traffic Emergency Disposal

With large traffic volume and high driving speed on freeway,once an accident happens,it will cause severe injuries to vehicles and people.After a traffic accident,a reasonable emergency disposal scheme can effectively reduce the losses caused by the accident.However,due to the limited rescue service sites and the lack of rescue resources and so on,it is difficult to provide timely and effective rescue service,which ultimately results in severe losses.Moreover,the traffic accident will lead to a decline in the capacity of the accident site.When the vehicles are in a heavy queue,they will also affect the overall road network operating efficiency.Under these conditions,based on the layouts and resource allocations of the existing rescue sites,this paper will discuss the two key issues including emergency vehicle deployment scheduling model and traffic induction under traffic accidents.Firstly,according to the accident information of freeway accidents in Shaanxi Province,statistical analyses were made on the delay time of five common traffic accidents.On this basis,in overall consideration of the difficulty of emergency response,the capacity of accident site and the queue length of vehicles,the accident impact classification based on the perspective of emergency treatment is proposed to provide reference to determine the emergency vehicle resources required for the accident.Secondly,through researches and researches by relevant scholars,five kinds of emergency vehicles quantification models have been proposed,which determine the emergency resources required for the accident.Then,the three scheduling methods of the Hungarian,direct cost,opportunity cost of emergency vehicles are analyzed theoretically and compared with case studies.The applicable conditions proposed through accident impact scope,rescue demand and potential cost have enabled the reasonable dispatch of emergency vehicles.Finally,based on traffic wave theory,the temporal-spatial incidence of traffic accidents on road network is analyzed.At the same time,the method of determining the divergence node and path is studied.From the perspective of the overall operating efficiency of the road network,the selection evaluation index of the induced area and the determining process are proposed.On this basis,TransModeler simulation software is used to establish the road network model of Hanning Freeway and other connected roads to simulate two kinds of induction schemes after traffic accidents.According to the induced regional evaluation criteria,emergency disposal point is determined.The simulation results show that: Compared disposal plan 1 with the case where the accident is not induced,the vehicle density of the accident road section and the total delay time of the road network are significantly reduced,and the overall operating efficiency of the road network is significantly improved.This paper has important significance for improving emergency response capacity of freeway by solving the two key problems of emergency response.