Robustness Analysis and Optimization Strategy of Urban Bus Network Based on Complex Network

The bus system plays an important role in the urban public transportation infrastructure system, providing a convenient way for the masses to travel. However, the operational resilience and functional stability of urban transit systems are frequently jeopardized by a variety of internal disruptions and external emergencies. Therefore, it is important to evaluate the robustness of urban bus networks. Based on the complex network theory, this research applies Space L and Space R methods to construct the bus stop network and bus line network models in Jinan, China. The topological characteristics of the two network models are studied, and the network robustness is analyzed using two attack strategies: random attack and deliberate attack. The robustness is optimized based on the network edge addition strategy. The results show that: (1) The bus stop network has a scale-free network property, but the bus stop network and the bus line network do not have the small-world network property. (2) The bus line network is more robust than the bus stop network when under attack, and the network under deliberate attack is more vulnerable than that under random attack. The maximum betweenness centrality node attack causes the most significant damage to the network. (3) Under random attack, both high betweenness centrality edge addition (HBA) and high degree edge addition (HDA) strategies are more effective at optimizing network robustness; under maximum degree node attack, both low betweenness centrality edge addition (LBA) and low degree edge addition (LDA) strategies are more effective on optimizing network robustness; under maximum betweenness centrality node attack, the LBA strategy has the best effect on optimizing network robustness. The research results can provide scientific guidance for the emergency scheduling and line optimization of urban public transportation system.