Impact on Bus Ridership from Changes in a Route's Span of Service

Ridership response to changes in a bus route's span of service—the start time of the first trip to the end time of the last trip each day—was examined specifically for hours that were not altered by a change in the span of service. Data were obtained for 39 routes from nine transit agencies in the western United States that experienced changes in the span of service without any other types of changes to enable the largest known analysis of such data from American transit systems. Results demonstrated that bus routes receiving an increase in the span of service experienced a 12.4% increase in ridership during unaltered hours (a 3.4% increase in ridership during unaltered hours after adjusting for systemwide rider-ship changes). Bus routes that received a decrease in the span of service experienced a 0.1% decrease in ridership during unaltered hours (a 1.5% decrease in ridership during unaltered hours after adjusting for systemwide ridership changes). Possible reasons for ridership increases following a span decrease that occurred in some samples were explored. The agency that implemented the largest collection of span increases experienced simultaneously the largest percentage increase in rider-ship during unaltered hours and thereby showed similarity to another large span increase outside the United States, a parallel that indicated a potential synergistic effect warranting additional research. Other factors present in routes that experienced relatively strong ridership responses during unaltered hours are also presented for agencies to consider when possible changes to service spans are evaluated.