Simulation on Survivability and Cascading Failure Propagation of Urban Subway-Bus Compound Network

To study the topological characteristics of urban public transit compound network, the validity of urban subway-bus compound network in Chengdu under attack&congestion was analyzed by constructing multimode topology network. Through the complex network theory, firstly, the static invulnerability of urban subway-bus compound network under different attack modes was tested to judge the importance degree of relevant nodes and lines. Then, the propagation of network overload and/or congestion, the cascading failure process under subway emergency were measured, so as to estimate the emergency coordinative performance of the ground public transportation system adjacent to metro lines. The results indicate that compound network has better overall efficiency than single network according to the lower decreasing amplitude and speed droop of the indices of network efficiency under random and intentional attack. In the opinion of the simulation results of cascading failure features of eight metro lines in Chengdu under the emergency episode with&without restrictive capacity, the emergency response capability of the bus lines system along the metro lines can be measured and judged effectively, in order to implementing pointed and efficient strategies&measures to handle the flow overload of the compound network arising from sudden accidents.