Research On Key Intersection Identification Considering Capacity Limit Of Evacuation Terminal

In the past ten years,my country’s economy has developed rapidly,the rate of urbanization has been accelerating,and the frequency of emergencies in cities has increased.At the same time,the rapid popularization of private cars in my country has brought huge challenges to the urban road network.In the face of the increasingly prominent contradiction between traffic supply and demand and the fragile traffic network,formulating a reasonable and efficient evacuation plan is particularly important for mitigating losses caused by disasters.The emergency evacuation plan of the traffic road network is an important part of emergency evacuation.The emergency evacuation traffic flow allocation strategy mainly includes user equilibrium(UE)and system optimization(SO).However,in the existing emergency evacuation traffic flow allocation research,the system is optimal The(SO)allocation strategy must be under the condition that all intersections have traffic control facilities,in order to achieve the system’s optimal flow distribution in the road network,and achieve the goal of minimizing the total emergency evacuation time.However,in reality,due to the limited resources of traffic control facilities,it cannot fully cover every intersection for control.Based on this background,in order to solve this urgent and practical problem,this article studies the emergency evacuation road network for insufficient traffic control resources.At the same time,considering the fact that the evacuation terminal capacity is limited,some special control key intersections in the road network are identified,and limited traffic control facilities are allocated to the key intersections for optimal traffic flow distribution,so as to achieve when close to all intersections are controlled.The optimal state of the system(SO).It has important practical significance for effectively reducing the time cost of disasters to evacuees,reducing the losses caused by disasters,maximizing the use of emergency resources,and realizing humanized rescue.First,this article analyzes the current research status of international and domestic emergency evacuation strategies,expounds the research methods,content and models of domestic and foreign scholars on emergency evacuation strategies,puts forward the shortcomings of the current research status,and introduces the research content,practical significance and technology route.This paper analyzes the complexity of the traffic network,proposes the definition of key intersections in the evacuation road network,and deeply analyzes the traffic flow characteristics,evacuation management strategies and plans during emergency evacuation.Based on the research on the optimal allocation of resources at key intersections,this article explains the types of intersections in the urban road network,the traffic control at key intersections,and the calculation method of the evacuation terminal capacity,and further understands the identification of key intersections in the evacuation road network.The purpose and practical significance of considering the evacuation terminal capacity limit.In addition,this article combines the basic theories of graphs and networks in operations research to abstract the traffic network structure as a network diagram.The actual evacuation starting point,intersection,and evacuation end point are replaced by nodes in the network.The edges in the network represent road segments.The method can visually show the structure of the evacuation road network.In the modeling process,it is proposed that travelers follow the system optimal(SO)allocation strategy at intersections with intact traffic control facilities,and follow the user equilibrium(UE)traffic allocation strategy at intersections with no traffic control facilities or damaged traffic control facilities.,Under the condition of traffic control resource constraints,follow the allocation strategy of the combination of system optimization(SO)and user equilibrium(UE).Based on this theory,this paper comprehensively considers the actual situation of traffic control resource constraints and limited evacuation terminal capacity,with the goal of minimizing the total evacuation time of the road network,and constructs a key intersection identification model considering the evacuation terminal capacity limitation.This paper takes the evacuation plan of Lanzhou Petrochemical Synthetic Rubber Plant as an example to analyze the rationality of the model.It starts from three stages: background investigation,model solving and result analysis.The investigation part mainly obtains basic information such as the road network map of the surrounding area of Lanzhou Lanshi Rubber Factory,the distribution map of emergency shelters in Lanzhou Xigu District,and road network parameters;the model solving part is the algorithm design of the actual data of the investigation,and the best model is obtained.Optimal solution;the result analysis is to analyze the results obtained from the model solution,and finally identify the key intersections in the evacuation road network around the Lanshi Rubber Factory,propose a targeted emergency traffic management traffic flow distribution plan,and verify the constructed model and The universality of the algorithm in the actual road network.