Improving transit service quality and headway regularity with real-time control

Disrupted transit operations are often caused by stochastic variations of passenger demand at stations and traffic conditions on service routes, which increase passenger wait times and thus discourage passengers from using the transit system. Efficient, real-time operational control is desirable to maintain headway regularity and reduce the negative effects of service disturbance. A real-time headway control model is proposed to maintain desired headways for pairs of successive vehicles by minimizing total headway variance for all stations in an advanced public transportation system environment, such as an automatic train control system and an automatic vehicle location system. A vehicle's departure time can be adjusted on the basis of its optimal arrival time at the next station, while considering the maximum attainable operating speeds and the headways to its leading and following vehicles. The proposed real-time control model is tested by simulating a high-frequency light rail transit route in Newark, New Jersey. The simulation results demonstrate that the average passenger wait time is significantly reduced after applying the control model.