Improving service restoration using automatic vehicle location

57 p.This study investigates important issues in transit service reliability, namely large service gaps and bus bunching. Using automatic vehicle location (AVL) data from the Route 20 ? Madison bus route of the Chicago Transit Authority (CTA), the primary focus is on identifying and establishing conditions that indicate a large service gap is imminent. In addition, the spatial and temporal patterns of large service gaps along the route are illustrated, along with the degree to which large gaps and bunching propagate down the route. Recommendations for improving the service restoration approach at the CTA are also presented based on the AVL data analyses, field observations at the CTA, and interviews with key members of large transit agencies across the United States. Among the recommendations is the implementation of a flag system, which notifies control center personnel that a large service gap is likely to occur so that preventive action can be taken