Parameter Selection and Evaluation of Robustness of Nanjing Metro Network Based on Supernetwork

Metro plays an important role in an urban public transport system. With the use of metro lines, the increasing flow of people has brought tremendous pressure to the operation of metro lines, resulting in different faults, thus affecting the travel of residents. How to qualitatively evaluate the robustness of the metro network after encountering faults is a problem worthy of attention. By 2018, ten metro lines have been opened in Nanjing, forming a radiation structure from the urban center to the surrounding suburbs. In this study, the metro faults in Nanjing in the past three years are counted and classified. The space L and space P models for the metro network are constructed. The robustness of a Nanjing metro network is measured by the three indicators: network connectivity efficiency, largest connected subgraph size, and average subgraph size. The concept of supernetwork is proposed, and the metro line is considered as a whole. The robustness changes of the Nanjing metro network caused by the attacks on the nodes and hyperedges of the metro network are analyzed. The results show that deliberate attack causes more damage than a random attack. When traffic hub stations and trunk lines are attacked, the performance of the metro network will decline sharply. The research conclusion has certain practical value to enhance the anti-fault ability of the metro network.