Vulnerability assessments of urban rail transit networks based on extended coupled map lattices with evacuation capability

This paper proposes the evacuation capability of station to design the extended coupled map lattices and analyzes the passenger dynamics and station states of urban rail transit networks subjected to the external disturbances. Meanwhile, the commuting ability of station is designed to study the topological vulnerability and the residual flow ratio of passenger flow is involved to study the functional vulnerability of urban rail transit networks. Moreover, three malicious attacks are used to imitate the external disturbances, and Shanghai metro network is taken as the example to illustrate the feasibility and effectiveness of the proposed model. The results show that urban rail transit networks have certain robustness subjected to the external disturbances and the global cascading failures will take place when the external disturbance R >= 2.6, which indicates that R = 2.6 is the critical threshold of external disturbances to smash urban rail transit networks subjected to three malicious attacks. By comparisons, we can declare that the nodes with the highest betweenness and the largest degree must be provided more protections in daily operation of urban rail transit networks, and the topological structure has a greater impact on network vulnerability compared with transportation function.