Exploring the comprehensive optimization model for location strategy of bridging depots based on metro vulnerability and information entropy

As the backbone of the metropolis, the metro is developing towards networking and complexity. Random and unpredictable emergencies will significantly impact the metro and transportation network. At present, the emergency bridging bus is an important strategy to ensure the reliability of the metro system, and the depots are the primary source of the bridge bus. Whereas, the previous research on the location of the depots does not consider the randomness of emergencies and the reliability of the new transportation system after adopting the bridging strategy. To fill the research gap, we propose a multi-objective optimization model for depot location based on metro vulnerability and information entropy evaluation theory. First, according to the topological structure of the metro, passenger demands and other factors to obtain the importance of network nodes. Secondly, the information entropy evaluation method is innovatively proposed to evaluate the network performance after the location of the depots from three perspectives: the network adjacency attribute, the ability of the depots to transport the bridging bus to the interrupted interval, and the rescue ability of the bridging buses dispatched by the depots. Finally, a multi-objective optimization model is established with optimal network performance and minimum depots construction cost. The results show that the model proposed in this paper can provide a better bridging effect and reduce passenger delay while effectively reducing construction costs. The study can notedly provide suitable and operable location strategies for urban traffic managers.