Trip frequency scheduling for bus route management in Bangkok

The public bus transit system of Bangkok is one of the largest in the world and operates in a very hectic traffic environment. The development of a specific and computerized trip frequency scheduling mechanism is required to provide good service at minimal cost. Trip frequency scheduling is studied taking into account the present practices, limited bus fleet size, lack of parking spaces, the fluctuating traffic conditions throughout the day, and the special feature that buses and crews are not pre-assigned to specific trips by the beginning of the daily operation. An integer programming model is developed and two heuristic methods, one of which is based on linear programming and the other being a straightforward derivation of common bus operation practice, are presented. The resulting methodology is tested on two selected bus routes in Bangkok and extensive comparisons are made. In this case study, it appears that schedules can be designed which simultaneously reduce exploitation costs and improve service to the public. The methodology allows the bus company to systematically plan all its bus frequencies and to allocate buses to routes in a much more efficient way than at present.