Structural characteristics analysis and cascading failure impact analysis of urban rail transit network: From the perspective of multi-layer network

Most of the previous works abstracted the urban rail transit network (URTN) as a single-layer network, which does not fully consider the characteristic difference of each single line, the dependence among different lines, and the heterogeneity among different lines and transfer channels. Hence, we abstract each urban rail transit line as a single layer, the stations of the line are abstracted as nodes and the interval between adjacent stations is abstracted as an edge of a single-layer network. Transfer stations in different layers are connected and forms the transfer edges. Based on the established multi-layer directed weighted (time) network, we establish the structural characteristic analysis indexes including node degree, node betweenness, node efficiency, edge betweenness, layer betweenness and layer dependency. We add a new land layer network into the established multi-layer directed weighted network, and conduct cascading failure analysis on passenger travel considering node failure, edge failure and line failure, respectively. Two indicators including Passenger Travel Efficiency Ratio (PTER) and Passenger Flow Pressure of Lines (PFPL) are proposed to evaluate impact of cascading failure on network. A case study is conducted by using Chengdu Metro Network as the background. The results show that the proposed methodology is reasonable and effective.