Research on Accessibility Optimization of the Last Train of Metro Based on Minimum Cost

The dynamic nightlife scene has resulted in a significant increase in late-night passengers utilizing the metro system. However, efficiently serving these passengers during their last train connections in metro while minimizing costs poses a challenging task for operators. To address this challenge, this study employs CPLEX to develop a linear mixed-integer programming model. The model aims to optimize metro network by maximizing the number of connected transfer directions while minimizing adjustments to departure time of the last trains. The results reveal that optimizing the transfer stations on weekdays has led to a remarkable 13.0% increase in the number of connectable paths within the metro network. Notably, only minor adjustments to the departure time of three lines were necessary, resulting in an ideal cost outcome. Furthermore, during special events, strategically delaying the departure time of specific routes resulted in a significant improvement of 18.0%. This outcome demonstrates the model’s excellent effectiveness in optimizing the system.