A Dynamic Approach to Eliminate Bus Bunching

Bus schedules cannot be easily maintained on busy lines with short headways: Experience shows that buses offering this type of service usually arrive irregularly at their stops, often in bunches. Although transit agencies build slack into their schedules to alleviate this problem − if necessary holding buses at control points to stay on schedule − their attempts often fail because practical amounts of slack cannot prevent large localized disruptions from spreading system-wide. This paper describes an adaptive control scheme to mitigate this problem. The new scheme dynamically determines bus holding times at a route’s control points based on real-time headway information. The method requires less slack than the conventional, schedule-based approach to produce headways within a given tolerance. This allows buses to travel faster, reducing in-vehicle passenger delay and increasing bus productivity.