Activity-Based Travel Models and Transportation Equity Analysis Research Directions and Exploration of Model Performance

The current state of practice for transportation equity analysis is moving toward the use of activity-based travel models for scenario analysis. However, little has been done to validate the use of these models for equity analysis. The first objective of this paper is to present a research framework for the equity analysis of long-range transportation plans, for the purpose of critiquing the current state of practice and pointing to key research needs. This research framework is used to identify four research areas for furthering transportation equity analysis: (a) identifying transportation priorities for different groups of interest, (b) identifying appropriate modeling tools for measuring equity outcomes, (c) identifying and analyzing equity indicators, and (d) linking the equity indicators and the transportation priorities. The second objective is to explore how well an activity-based travel demand model represents heterogeneity of travel behavior among different income classes, for the purpose of transportation equity analysis. Graphical and statistical tools are used to access how well a sample of the model data compares with a sample of travel survey data for the San Francisco Bay Area in California. The results show that although the tests of distribution equality fail, the general shape of the distributions, the central tendencies, and the relative difference of the low- versus high-income samples perform well.