Project Summary
Vehicle miles traveled (VMT) is a well-accepted measure of the amount of travel taking place on a transportation system and thus, that system’s climate impacts and sustainability characteristics. California Senate Bill (SB) 375 establishes a process for setting regional-level targets to reduce VMT, which necessitates incorporating VMT-based analysis into transportation planning and modeling in practice. The issue is whether VMT needs to be further classified into “types of VMT” that can be incorporated into the process to provide more sensitive policy analysis. Trips differ in both their purpose and in the mode or vehicle used, and consequently, VMT can be viewed as better or worse for economic productivity and sustainability based on these characteristics. For example, some car trips can be accomplished with web-based devices. Little research has pursued this notion for policy-making purposes. Using available data on trip purposes, and on vehicle mixes (in terms of fuel usage and environmental impact) used for trips, productivity-based indices can be developed to properly assess the environmental/energy impacts of the VMT associated with broad classes of trips.
This project utilizes various data sources and an existing transportation system planning and analysis model (for a selected case study network) to develop methods for identifying and prioritizing potential VMT categories. Researchers will then use this information to evaluate the impact of different policies. This initial study will also serve as a trial for larger studies to evaluate system-wide policy implications. VMT category-based pricing, subsidy, taxation and land-use policies can be tested in selected network case studies. One simple example would be taxing VMT from electric vehicles less than gasoline powered vehicles.