Informing Transportation Investment Decisionmaking

The transportation investment decisions made by federal, state, and local governments can have a significant effect on greenhouse gas (GHG) pollution outcomes. For example, investing in expanding roads tends to lead to more driving, which means more emissions. On the other hand, investing in infrastructure to support an expanded range of transportation options, such as walking, biking, and public transit, can lead to lower emissions. Policy actions across levels of government are needed to ensure that transportation spending helps — and does not hurt — efforts to reduce GHG emissions through investments that expand access to clean and affordable transportation systems. 

The Georgetown Climate Center supports state, local, and federal action on transportation by bringing together policymakers and stakeholders and providing cutting-edge research and analysis that is designed to inform decisionmaking. This includes:

  • Identifying opportunities to prioritize funding for low-carbon transportation projects and improve transportation investment decision making;
  • Providing analysis and tools to help policymakers understand the connections between spending on transportation infrastructure and real-world outcomes, including changes in GHG emissions and other air pollutants; 
  • Convening focused policy discussions that make it more likely that good ideas become policy, including forums for policymakers to talk with each other, share ideas, and explore lessons learned and best practices; and
  • Supporting the efforts of policymakers working to better align climate goals with infrastructure investment decisions. 

Identifying opportunities to prioritize clean, affordable transportation options 

Federal funding flexibility

Georgetown Climate Center has provided legal analysis to help policymakers and stakeholders better understand the flexibility that state and local governments have when spending federal transportation dollars. Our issue brief, “Flexible Federal Funding Opportunities for State and Local Clean Transportation Investments,” describes ways that states can leverage the flexibility built into federal law to use federal funding to support climate-smart infrastructure projects. 

Integrating climate and transportation planning

Many important decisions about transportation investments are made during statewide and metropolitan transportation planning processes. These processes are largely guided by federal law, which requires state and local planners to adhere to a data-driven, performance-based approach to planning. By taking steps to integrate climate considerations throughout the transportation planning process, state and local planners can take steps to better align transportation funding decisions with achieving their climate goals.    

A growing number of states recognize the opportunity to connect transportation decision making with other GHG emissions reduction strategies. Georgetown Climate Center is supporting and tracking these developments through a variety of projects and publications, including:

Providing analysis and tools to better understand the connections between transportation investments and GHG emissions

Legislative analysis

To inform the national conversation around how to best spend the historic levels of federal transportation funding authorized by Congress through the most recent transportation funding bill, the 2021 Infrastructure Investment and Jobs Act (IIJA), the Georgetown Climate Center estimated how the bill’s surface transportation provisions could affect GHG emissions outcomes. Our analysis found that the funding authorized by the IIJA could be an important part of the U.S. response to climate change, or it could lead to more GHG pollution than the then-current national trajectory. According to the analysis, the actual outcome within that range would likely depend on the investment decisions made by state and local governments. The fundamental insights we detailed in that analysis hold true for any state or federal surface transportation investments: 

  • If transportation investment decisions prioritize a “fix it first” approach and emphasize maintenance of existing roadways, along with investments in transit, electric vehicles and charging infrastructure, and other low-carbon transportation options, this historic infusion of federal funding has the potential to accelerate reductions in GHG emissions from surface transportation relative to business as usual.
  • But if investment decisions are made without consideration to the emissions outcomes, including by adding substantially more lanes and roads, the federal funding could result in an increase in emissions over what we’d expect without this additional investment. That’s because building more roadway capacity consistently results in more traffic — an “if you build it, they will come” effect known as “induced demand.”

Building on our nationwide IIJA analysis, GCC applied a similar method to estimate the scale of emission reduction opportunities at the individual state level. In 2023, Georgetown Climate Center partnered with RMI to analyze federal transportation funding investment scenarios in twelve states. We found that all states had an opportunity to reduce emissions if decision makers minimized expanding highways and prioritized funding low-carbon transportation strategies. In May 2023, Georgetown Climate Center published a similar analysis of the IIJA’s potential to reduce GHG pollution from transportation in New Jersey.

Transportation Evaluation and Carbon Reduction Tool (TEA-CART)

The Transportation Evaluation and Carbon Reduction Tool (TEA-CART) is a planning-level tool capable of estimating how transportation investments will affect future emissions as a result of vehicle electrification, changes in Vehicle Miles Traveled, Passenger Miles Traveled, “fix-it-first,” and other strategies. TEA-CART was developed by Georgetown Climate Center in partnership with Cambridge Systematics, with extensive input by state and federal officials. It is designed to help state DOT practitioners account for the environmental performance of their projects, so they can set meaningful electrification, VMT and GHG-reduction targets and develop capital plans that prioritize low-carbon transportation projects. The tool is highly customizable, accepting simple inputs to easily evaluate the performance of capital projects during the planning or programming stage. Learn more about TEA-CART.

Supporting progress toward climate goals 

Sustainability Network 

Since 2023, Georgetown Climate Center has partnered with the State Smart Transportation Initiative to co-facilitate the Sustainability Network, a group of state DOT officials from across the country that share a common interest in improving multimodal access and managing travel demand. The Sustainability Network convenes at least once a month, and members are encouraged to share updates and engage in peer-to-peer learning, including by developing and advancing best practices for expanding access to more equitable multi-modal transportation systems. 

Clean RIDES Network

The Georgetown Climate Center participates in the Clean RIDES Network, which includes dozens of organizations working to make transportation systems more affordable and sustainable through strategies that cut costs for families, curb air pollution, and shorten commutes. GCC contributes by conducting independent policy research, technical analysis and modeling to illustrate how transportation policies and investment strategies meaningfully affect emissions outcomes. As described above, we also develop and disseminate tools — like TEA-CART — that make it easier for state officials and public stakeholders to account for the GHG performance of transportation investments.

Additional Resources

Under the Biden Administration, the U.S. Department of Transportation (USDOT) published a number of resources designed to aid transportation decision makers in reducing transportation sector GHG emissions, including:

The National Cooperative Highway Research Program (NCHRP) has also published research on methods and strategies for state and local transportation agencies to reduce transportation sector GHG emissions, including: