Methods for Assessing the Effectiveness of Potential Vehicle-Miles-Traveled (VMT) Mitigation Measures

Project Description

May 2022 - April 2024

Under the Transportation Analysis Framework (TAF), developed in response to SB 743, Caltrans must analyze the impacts of projects on the State Highway System (SHS) on vehicle-miles-traveled (VMT) as a part of the environmental review process under the California Environmental Quality Act (CEQA).  The goal of this project is to develop guidance and methods for assessing VMT reduction for various potential mitigation measures for SHS projects. The first objective of the project is to develop a list of potential mitigation measures drawn from existing sources and with input from stakeholders, that may be appropriate for VMT mitigation for SHS projects; an explanation of the role that Caltrans can play, directly or indirectly, in their implementation; and a discussion of the contexts in which they are most appropriate and effective.  The second objective is to assess methods for estimating the effectiveness of potential VMT mitigation measures. Methods to be assessed include regional travel demand forecasting models, “off-model” adjustment methods, the California Air Resources Board’s quantification methods, the updated CalEEMod tool, and others. The third objective is to explore the possibility of developing an accessibility tool that can be used for estimating the effects of VMT mitigation measures.