Study On Identification And Protection Of Key Nodes In Urban Road Traffic Network

How to effectively identify the key nodes in urban road traffic network is one of the important technical problems in the field of urban traffic control and emergency management.In this paper,the connotation of the key nodes was defined,and the change value of the total travel time of the road network traffic flow before and after the nodes' failure was taken as the quantization value of the importance degree of the node.The factors influencing the importance degree of the nodes were analyzed from the angle of network topology and the characteristics of traffic operation;the correlation between the importance degree and the influencing factors was tested by using the regional road traffic network data of Shenyang city to determine the evaluation of key intersections index set.Finally,the key node identification method based on projection pursuit analysis is designed,and the case analysis of Shenyang regional network is carried out to prove that the proposed method is feasible and effective.Then this article analyzes the protection measures of key nodes from road network and travel network,including measures such as closing intersections,closing roads,adding roads,etc.But considering that the key nodes are dynamic and change in real time,the complex network is used Based on the node-protected weighted routing strategy,a new weighted road network based on the degree of importance of nodes is constructed.Combined with the travel time network,a weighted routing strategy is proposed.In the new weighted road network constructed,by constantly adjusting the value of the coefficient,the weight of the edge connected to the key node is increased,so that the vehicle can avoid the key node.In the end,the paper analyzes some examples of road networks in Shenyang City,gradually changing the mediation coefficients and using the user equilibrium allocation model to redistribute the traffic.It is found that as the mediation coefficient increases,the traffic at key nodes gradually decreases.Therefore,based on the travel time road network,when the route guidance is performed,the vehicle can effectively avoid the key node,thereby preventing the key node from being jammed.