Evaluating Operational and Structural Optimization Strategies for Metro Interchange Stations Using Passenger Flow Simulation

A Case Study of Liyuan South Road Station

Abstract

While operational and structural optimizations for metro stations are well-studied individually, their synergistic effects and resilience under extreme conditions remain poorly understood. This paper establishes a systematic „simulation-optimization-evaluation” framework to quantitatively assess and compare the robustness of different intervention strategies. Taking Liyuan South Road Station of the Ningbo Metro as a case study, we evaluate three scenarios: 1. operational adjustments, 2. structural modifications, and 3. an integrated approach. While the integrated scenario yields the most significant density reduction (9.39% on average, 2.31% in maximum density) under forecasted peak flows, its primary advantage lies in its resilience. Stress tests reveal that the integrated scenario maintains safe operational levels even when passenger flow reaches 1.7 times the forecast, whereas the original and single-strategy scenarios exhibit severe congestion at flow multipliers of 1.3 to 1.4. This study demonstrates that the proposed framework is a valuable tool for decision-makers, enabling a holistic assessment that balances efficiency, safety, and resilience against future demand uncertainty. The findings confirm that integrated strategies, despite marginal increases in transfer times, provide superior safety margins and are essential for the long-term sustainability of high-traffic interchange hubs.