Development of time-of-day-based transit accessibility analysis tool

The measurement of transit accessibility and availability is important both for forecasting transit ridership and for planning and evaluating transit service. When measuring transit accessibility, both spatial and temporal dimensions of demand and supply are important considerations. Between these two dimensions, the temporal dimension has lagged behind the spatial dimension with respect to its explicit recognition and incorporation in transit accessibility measurement. A transit accessibility measurement tool has been developed that explicitly considers two facets of the time dimension. Considered first is the supply side of the time dimension by incorporating the span and headway of service and the willingness to wait to determine the actual time duration when service is truly available to potential riders. Next considered is the demand side of the time dimension by incorporating the time-of-day distribution of travel demand to determine the relative value of the transit service provided in each time period of the day. The tool measures transit availability with regard to the daily trips per capita in each zone that is exposed to transit service. The flexible spreadsheet-based tool can be easily and quickly applied at the local level in support of service planning and service delivery analysis. The application of the tool is demonstrated with a simple numerical illustration.