Urban Road Network Vulnerability Evaluation Based On General Travel Cost

Urban road network as a skeleton of the transport system,the development of the city has a crucial role.But in the natural disasters,large-scale activities,traffic accidents,road construction and other events under the influence of the road network part of the road may be invalid,serious,the whole road network even paralyzed.Scientifically evaluate the vulnerability of urban road network,for the improvement of road sections,the urban road network optimization has important guiding significance.At present,the research on the vulnerability of urban road network has made many achievements,but there are still some shortcomings.The network effectiveness index and network travel cost index based on general travel cost proposed in this paper can describe the performance of the whole network network more accurately.This paper focuses on the evaluation of urban road network vulnerability,mainly to carry out the following work:Firstly,this paper defines the vulnerability of urban road network and its related concepts,defines the vulnerability as the sensitive degree of performance affected by the external disturbance,and analyzes the mechanism of vulnerability.From the perspective of qualitative and quantitative Analysis of Factors Affecting Vulnerability of Urban Road Network.Secondly,the definition of generalized travel cost is given for urban users,and the general travel cost model considering consumption,time and comfort is established.By using SP and RP survey method,the characteristics of user travel in Harbin are analyzed,In order to improve the efficiency of the evaluation,the topological index and the link attribute index are used to establish the importance index of the road section,and the 20% of the section of the index is selected as the key road segment.In this paper,the model is calibrated by deleting the road segment.The paper introduces the network effectiveness index and the network travel cost index based on the general travel cost,and analyzes the network effectiveness and the network travel cost to remove the change rate before and after the key road segment,and then evaluate the vulnerability of the network.Finally,the author chooses a local road network in Harbin,and uses the theory and method proposed in this paper to simplify the road network,calculate the importance index of road sections,identify the key sections in the road network,and use the UE model to carry out the traffic Distribution,before and after the road to delete the network validity and network travel costs,so the vulnerability of the road network evaluation.