Advancing the practice of regional transportation equity analysis: a San Francisco bay area case study

Abstract

AbstractAs the transportation industry continues to evolve, it is urgent that we develop and implement methods for clearly evaluating the range of transportation engineering, planning, and policy impacts experienced by various population segments. While theories of transportation equity have advanced over the past decade, such advancements outpace existing methods for evaluating the fairness of large-scale transportation investments for disadvantaged communities. In this study, a regional activity-based travel model for the Bay Area, California is used to perform an equity analysis of two of the region’s transportation and land-use planning scenarios. Equity outcomes are tested relative to three equity standards: Equality, Proportionality, and Rawlsian justice. The primary objective is to demonstrate the usefulness of a full-scale activity-based travel model for regional transportation equity analysis. We demonstrate that fine-grained distributional measures play an important role in examining the individual and household-level impacts of regional transportation scenarios, and can complement existing Environmental Justice assessments and equity analyses by helping to explain underlying reasons for average group impacts. Distributional measures can further reveal harmful cases when disadvantaged groups are most likely to experience the disbenefits of the transportation scenarios. Yet, each type of measures in isolation does not tell the complete story of which planning scenario is likely to deliver more equitable outcomes. Finally, we demonstrate the significance of applying equity standards for ranking planning scenarios, and we find that the ranking of scenarios will vary according to the equity standard, as well as how associated evaluation criteria are defined.