Comparing two common approaches to public transit service equity evaluation

Understanding the equity effects of transit service changes requires good information about the demographics of transit ridership. Both on-board survey data and census data can be used to estimate equity effects, though there is no clear reason these two sources will result in the same finding of impact. Guidance from the Federal Transit Administration (FTA) recommends using either of these data sources to estimate equity impacts. This article makes a direct comparison of the two methods for the public transit system in the Phoenix, Arizona metropolitan area. The results indicate that, although both sources are acceptable for FTA compliance, the use of one or the other can affect whether a proposed service change is deemed equitable. In other words, the outcome of a service change equity analysis can differ depending on the data source used. To ensure the integrity and meaning of the analysis, FTA should recommend the collection and use of ridership data for conducting service change analyses to supplement census-based approaches.