Robustness Analysis of an Urban Public Traffic Network Based on a Multi-Subnet Composite Complex Network Model

Area of Science:

• Complex network theory
• Urban transportation systems
• Network resilience

Background:

• Urban public transport networks are complex systems with diverse transport modes.
• Assessing network robustness is crucial for safe urban traffic operations.
• Existing models may not fully capture the dynamics of multi-modal transport networks.

Purpose of the Study:

• To develop a novel cascading failure model for urban public transport networks.
• To investigate the impact of different relationships and attack strategies on network robustness.
• To simulate and analyze the resilience of a real-world bus-subway composite network.

Main Methods:

• Construction of a multi-subnet composite complex network model.
• Introduction of a 'traffic function' concept to simulate traffic flow.
• Application of deliberate and random attack strategies to assess network robustness.
• Simulation using the Qingdao urban bus-subway network.

Main Results:

• Network robustness did not consistently increase with network capacity under attack.
• The proportion of multiple relationships between network subnets significantly influenced overall robustness.
• Both deliberate and random attacks revealed vulnerabilities in the composite network structure.

Conclusions:

• The proposed model provides a more realistic simulation of urban public transport network failures.
• Network capacity alone is insufficient to guarantee robustness; relationship structures are critical.
• Understanding the interplay of different transport modes is key to enhancing urban traffic system resilience.