Transit fares used in travel demand models are usually either full cash fares or some approximation based on the monthly pass and other fare types. This can sometimes result in an inaccurate representation of the fare paid by an average rider; particularly if a distance based fare structure is used by the transit agency and/or if the agency offers employee discount programs (EDP) for the employers around stations. Depending on the transit model structure and other characteristics of the transit system, the size of some of the key travel markets could be under- or over-estimated, thereby potentially distorting any forecasts made by the travel demand model. In this presentation, we will show an improved method of modeling transit fare. The method relies on on-board surveys that ask questions related to the fare type and fare medium used by riders.
A recent on-board survey conducted on the Tri-Rail commuter rail service in Southeast Florida is used to demonstrate the process of estimating the fare. Tri-Rail uses a zonal based fare (one-way, round trip, 12-trip or monthly fare) and also provides various fare types (full, discounted and EDP fares). Using the survey responses to the fare questions and the fare paid for each of the fare types, the authors estimated an average fare for each of the six zones used by Tri-Rail. In addition, the survey indicated that the fare paid by the riders differed by trip purpose. An adjustment based on trip purpose was also incorporated in the demand model. The average fare obtained from this analysis of the on-board survey data was utilized in the regional demand model. This method is also transferable to modeling fare on local bus systems.
Overall, this approach shows that estimating transit fare using information from on-board surveys results in a better representation of the average fare and hence better forecasts from the demand models. The results show a much better and accurate estimation of short trips on the Tri-Rail system. This is a direct result of accurately representing the competition between Tri-Rail fares and those offered by local buses when travel distances are shorter.