Bus Timetable Design to Ensure Smooth Transfers in Areas with Low-Frequency Public Transportation Services

This study investigates the timetable design problem in areas with low-frequency public transportation services. In Japan, rural areas face sparse populations and rapid growth in the percentage of elderly people. In these areas, many bus lines offer fewer than 10 services per day. In addition to low-frequency services, it is also inconvenient to transfer to another bus or train service. Thus, there is a strong need to design a timetable that ensures smooth transfers among buses and trains. We tackle this problem by adopting existing bus lines and train timetables as much as possible to avoid drastic changes such as an increase in the number of services. Based on this approach, we present a mathematical optimization model to generate a revised bus timetable that shortens waiting time for transfers compared with the current timetable. We apply our model to a part of the Tohoku District in Japan and demonstrate its usefulness in the real world.