Boarding space design for passenger evacuation with bus and e-hailing services under a surge in traffic demand

In densely populated urban areas, the spatiotemporal dynamics of public and private transportation lead to intensified competition for limited road space, especially during mass gathering events. To address this issue, we propose an optimal design for a bi-modal transport system that integrates e-hailing and bus services, balancing efficiency, economy, and safety. By incorporating traffic dynamics through Macroscopic Fundamental Diagrams (MFDs) in a bi-modal transport system, we capture variations in traffic flow and passenger behavior. At an aggregate level, the total generalized cost is modeled to include perceived trip costs, operating costs, and safety costs, which fluctuate according to time-varying traffic flow patterns. Through dynamic simulations, we evaluate four boarding space design scenarios. The results show that incorporating e-hailing services into large-scale events increases the complexity of dynamics and the risk of pedestrian accidents in a bi-modal transport system, adding safety costs for passengers. However, by designing separate boarding spaces for each mode, safety costs are significantly reduced, lowering the total costs. This also leads to a substantial reduction in the average cost of e-hailing trips. These findings provide valuable decision support for planning urban boarding spaces, improving service quality, and managing traffic congestion.