The Analysis Of Urban Road Network Vulnerability Considering The Effect Of Congestion

Since urban road network is the important carrier of urban traffic activities, more and more scholars are interested in the study of the network's vulnerability. In this paper, we consider the congestion effect in the process of urban road traffic network vulnerability analysis, during which we analyze the congestion in the network at the same time. So we can reduce the vulnerability of network by easing and controlling the traffic pressure.Firstly, how to construct the urban road network topology is expounded in this paper. In this paper, we use the Original Method to build the topology of urban road network. Then we expound the concept, connotation and the impact factors of urban road network vulnerability, analyze urban road network vulnerability from state vulnerability and structural vulnerability, which are very important for later vulnerability analysis process. Secondly, this paper is mainly about the change of the vulnerability and congestion degree in the urban road network during the cascading failure, which is caused by the failure of one road due to road congestion. To finish these works, we build the static and the dynamic mitigation models. In addition to this, we introduce the congestion factor. Thirdly, we consider the possibility of the key road to become congested. Then we consider that if the influence to network vulnerability is different when the cascading failure is caused by the key road and the non-critical road. Beyond that, we try to find the relationship between vulnerability and congestion. Finally, we proposed the methods to alleviate congestion to reduce the vulnerability: increased the design capacity, the distribution of spare capacity based on the importance of the roads and the regional one-way traffic Settings. We explore the relationships between the vulnerability and the degree of congestion of the network by analyzing the process of cascading failures in the transformation of road network and the original road network. And then we find that the three methods all above can reduce the network congestion degree and vulnerability to a certain extent.In this paper, we consider the change of the vulnerability and congestion degree in the urban road network during the cascading failure, which is caused by the failure of one road due to road congestion. We propose the methods to reduce the vulnerability of network by easing the traffic pressure. The methods are feasible, which can provide certain guidance for the management.