A double-weighted vulnerability assessment model for metrorail transit networks and its application in Shanghai metro

Abstract The vulnerability assessment of urban metrorail transit (or simply metro) networks is of great significance for a large scaled metro network to ensure the safe and sustainable operation. Comparing to the traditional model, this paper presents a modified double-weighted vulnerability analysis model for metro networks by taking account of the path distance and passenger flow as they are the two key features of a metro network. In this model, a link-weighted adjacency matrix was established based on which a node-weighted network efficiency was formulated considering the distance of path and the ridership between any two metro stations. The model was then applied to Shanghai metro to examine its vulnerability with failure scenarios at different scales from node failure, link failure to line failure. The network vulnerability was examined by the decrease in network efficiency. Results show that metro stations with high node degree and large ridership greatly contribute the influence on global network efficiency. It is identified from the double-weighted network model that Shanghai metro is more vulnerable to the failure of Lines 8 to 10, rather than Line 1, Line 2 and Line 11 obtained from the traditional unweighted network model. In this study, the most vulnerable metro stations, links and lines can be derived with consideration of path distance and passenger flow, which could provide guidance for reasonable resource allocation in system maintenance and aid the decision on recovery strategies for resilience of metrorail system.