Who, What, When, and Where

Public transportation agencies are faced with the difficult task of providing adequate service during peak travel periods while maintaining adequate service for those traveling off-peak or outside a city or region's densest areas. The ability or inability of a transit system to meet these needs helps explain transit ridership rates. This research sought to understand how daily fluctuations in transit service were related to ridership in the greater Toronto and Hamilton area, in Canada, for different segments of the labor force. Many variables—including frequency and proximity of transit service, socioeconomic status, the built environment, and accessibility to employment through transit—have been linked to transit use in past research. However, many previous studies focused only on travel during peak hours. This study investigated whether fluctuations in service and demand were related to transit ridership rates. With the use of six time periods, an improved understanding of daily variation in transit mode share for commuting trips was produced. With a further division of the commuting population into two employment wage categories, it was demonstrated that the common understanding of the influences on transit ridership was potentially misleading. Commuting transit mode share and the variables that influence it are intimately related to when travel is needed and to what jobs people are traveling. To encourage transit use, agencies and researchers need to take into account commuters’ need to commute at a variety of time periods.