A research study submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Engineering and Technology

Research Studies Project Report (M. Eng.) - Asian Institute of Technology, 1985

The purpose of this study was to find improved solution for bus scheduling and bus allocation for the Bangkok Mass Transit Authority. The bus scheduling problem was formulated as a minimum-cost-flow problem, and the bus allocation problem was formulated as a transportation problem. The out-of-kilter algorithm was used to solve both problems. A·· computer program was written to formulate a minimum-cost-flow network according to fixed timetable on the IBM 3083 computer. The size of the formulated network varied with the number of trips. The CPU time consumed to determine the optimal solution increased with the size of the network. However, this CPU time could be reduced by the reduction of the network size by using the simplifying techniques found in this study. After using these simplifying techniques, it was found that the solution of the bus scheduling problem with 534 trips, which initially consumed more than 90 minutes of CPU time, could be obtained within 5 minutes. Six BMTA air-conditioned bus routes which will be operated in April 1986 were taken to be a case study. It was found that the solution of this study is more efficient than that planned by BMTA. The number of buses required, the idle time of buses at termini and total costs were reduced. The number of unscheduled buses in the whole afternoon and the free time of buses at depots were increased. All of the air-conditioned bus routes were studied for the bus allocation problem. It was found that the total empty running distance could be reduced by 759 kilometers per day .