Millisecond-Scale Real-Time Scheduling of Buses: A Controller-Based Approach

Bus scheduling is vital for public transportation to ensure high transit service quality. In actual bus operation, buses’ travel time may change due to some uncertain factors, which makes the planned scheduling scheme fail to meet users’ actual requirements. This work proposes a Controller-based Bus Scheduling Approach (CBSA). In this approach, each departure time in a timetable is regarded as a decision point, and a controller is devised to select a bus in real-time to depart from the departure time. The controller makes a decision at each departure time to cover all departure times in a given timetable. The controller consists of a Duty Type Converter (DTC) and a Bus Selector (BS). DTC determines bus duty types to improve bus utilization, while BS selects a bus to cover the departure time. Since the controller makes decisions in a real-time manner, it can effectively handle uncertain events and factors (such as uncertain travel time). Some key parameters of the controller are optimized by a particle swarm optimizer (PSO) to improve its performance. CBSA is applied to real-world problem instances. Experimental results show that it outperforms the compared algorithms and a manual scheduling scheme. It can schedule buses in real-time to generate a high-quality scheduling solution under uncertain environments.