A practical approach to determine optimal bus frequencies: An empirical study of a bangkok bus service

This paper proposes a practical method to determine appropriate bus service frequencies using observed travel demand data. The paper introduces a simple rule to increase/decrease the bus frequency on each route during different service intervals. The approach considers minimum and maximum possible service frequencies based on an acceptable demand-capacity ratio, required level of service (i.e. waiting time), and available fleets. The optimal bus frequency is then determined to maintain a level of service which is measured by the revenue-cost ratio given a forecasted passenger demand profile. The paper proposes a rule-based expert system to estimate the daily demand for the bus services (for each time interval). An empirical case study with a bus service route in Bangkok is used to illustrate the benefit and performance of the proposed approach.