Passengers’ Perception of and Behavioral Adaptation to Unreliability in Public Transportation

Reliability is regularly cited by users of public transportation as one of the most important qualities of service. However, it is not yet well understood how transit riders are affected by unreliability, particularly in the long term. To gain a better understanding of the importance of reliability, a survey focusing on users of San Francisco's public transportation system in California was developed to investigate the link between people's past experiences of unreliability and the adaptation strategies that they used. Respondents were asked to rate the importance of a number of reliability aspects; the aspects found to be most important were the absence of a gap at a transfer stop and the ability to walk up to a stop and leave within 10 min. Users also reported that they considered reliability when planning trips. Common strategies for handling unreliability were using services and routes deemed more reliable and using real-time information. In addition, an ordinal logit model linking past experiences of unreliability to a reduction in transit use was estimated. The most significant negative experiences that drove a reduction in transit use were delays perceived to be the fault of the transit agency, long waits at transfer points, and being prevented from boarding because of crowding. These results have implications in transit planning: passengers may prefer more frequent service with occasional crowding over less frequent buses that are larger and less crowded. In addition, the growing use of real-time information services will continue to affect how people view transit service and perhaps even intensify the unattractiveness of infrequent service.