Impacts of Implementing Transportation Control Measures on Travel Activity and Emissions

Abstract

Transportation is one of the fastest-growing sources of greenhouse gas (GHG) emissions in the United States and is responsible for a large share of criteria pollutants as well. This paper describes the methodology and results from a project to analyze the potential national-scale effectiveness of transportation control measures in reducing GHG and other pollutant emissions through changes in travel activity. As part of the analysis, a peer-reviewed methodology was developed, and data were obtained from the regional travel demand models of 15 metropolitan planning organizations (MPOs). The regions covered a variety of city sizes, transportation profiles, and geographical regions of the country. The travel activity and emissions impacts of multiple strategies at the regional and national levels were estimated to 2050 with the data obtained from the MPOs. The strategies selected for analysis were travel demand management, land use policies, transit-related strategies, parking-cost changes, and road pricing in the form of vehicle miles traveled (VMT) fees. The long-range transportation plans of participating regions contributed to the creation of scenarios that combined the most widely considered strategies as well as more aggressive strategies such as road pricing for the analysis of impacts on regional trips and VMT. Although other research efforts have focused on this topic in recent years, this study is unique in its use of a bottom-up approach that employs data from a travel demand model for several metropolitan areas as inputs to a standard analysis tool. It helps to illustrate how the emissions impacts of transportation strategies can be estimated on a national scale by using regional information.