Theoretical Approach for Selection of Public Transport System Considering Urban Density and Travel Distance

The increasing popularity of ride-sharing services, car sharing, and other transportation options has led to a growing diversification of local public transportation services for short-distance travel. In this study, we aimed to understand how an appropriate public transportation system evolves based on density and travel impedance of passengers using an analytical model. Initially, we developed a model representing five typical transportation systems, each characterized by the presence of fixed routes and varying requirements for access and egress time. Subsequently, we analyzed the influence on expenses that satisfy the service level condition, focusing on the effect of demand density and travel distance. Furthermore, we investigated the current status of the introduction of local transportation in eastern Japan and compared the results with the calculation results of the model. Notably, we observed that increasing the number of buses and demand-responsive transit (DRT) operated by the local government led to enhanced effectiveness of car sharing, particularly in areas where DRT services were introduced.