Pursuing Multiple Goals in Transportation Policy: Lessons from an Integrated Model

The Transportation Climate Initiative (TCI)—a coalition of Northeast and Mid-Atlantic states and the District of Columbia—is currently negotiating a plan to promote clean transportation through a combination of carbon emissions cap, investment, and regulations. Although climate change is the main driver of this initiative, the jurisdictions involved also hope to address more immediate transportation concerns such as air quality, transportation access, and affordability. In this report, we exercise a modeling platform representing part of the TCI region to evaluate a set of transportation policy options, including carbon pricing and investments, for their performance along metrics relevant to these multiple transportation goals—carbon reductions, criteria pollution reductions, vehicle-mile changes, transportation availability, and distribution of costs across households. This report is not a direct analysis of the TCI program, nor is it intended to identify a single best policy or set of policies. Rather it highlights opportunities and trade-offs among multiple transportation goals that can inform a collaborative transportation planning process.