Comparison of two common approaches to public transit service equity evaluation

Abstract

Understanding the equity effects of transit service changes requires good information about the demographics of transit ridership. Onboard survey data and census data can be used to estimate equity effects, although there is no clear reason to conclude that these two sources will lead to the same findings. Guidance from the FTA recommends the use of either of these data sources to estimate equity impacts. This study made a direct comparison of the two methods for the public transit system in the Phoenix, Arizona, metropolitan area. The results indicated that although both sources were acceptable for FTA compliance, the use of one or the other could affect whether a proposed service change was deemed equitable. In other words, the outcome of a service change equity analysis could differ as a result of the data source used. To ensure the integrity and meaning of such analyses, FTA should recommend the collection and use of ridership data for conducting service change analyses to supplement approaches that are based on census data.