Transportation Agencies from 10 States and D.C. Voice Support for Federal Proposal to Track Greenhouse Gas Emissions from National Highways

October 13, 2022

States Across the Country Say Proposed Performance Measure Can Help Reduce Pollution, Improve Resilience of National Highway System

A busy highway with cars in traffic.

October 13, 2022 — In joint comments submitted to the U.S. Department of Transportation Federal Highway Administration (FHWA) today, transportation agencies from ten states and the District of Columbia expressed their support for a proposed federal framework to measure and set targets for reducing greenhouse gas (GHG) emissions from transportation on the National Highway System.  Signatories to the comments include leaders of the transportation agencies in the District of Columbia, California, Colorado, Connecticut, Hawaii, Illinois, Minnesota, Oregon, Pennsylvania, Vermont, and Washington, representing more than 95 million Americans or 29% of the US population. Transportation accounts for more than one quarter of all GHG emissions in the United States, more than any other sector. The joint comments were facilitated by Georgetown Climate Center, in collaboration with the signatory jurisdictions.

“As transportation officials, we recognize that the investments we make have the potential to support or delay progress toward reducing GHG emissions and avoiding the worst impacts of climate change,” write the signatory transportation secretaries and commissioners. “The proposed national performance measure for GHGs is an important action to complement and tell the story of the work that our states are doing to reduce GHG emissions from transportation.”  

The comments also offer technical recommendations for FHWA’s final rule, drawing upon state experience implementing existing federal performance measures, measuring GHG emissions, and setting emissions reduction targets. In addition to providing recommendations to ensure the proposed performance measure helps advance national and state emissions reduction goals and dovetails with ongoing state efforts, the joint comments articulate the following overarching points. (Excerpts provided in italics; full text of the comments is available here.)

I. The proposed Performance Measure is an appropriate tool for assessing GHG emissions from transportation on the National Highway System (NHS).

  • “FHWA’s proposed performance measure for GHG emissions represents an important step toward better understanding and accounting for the environmental effects of federally funded transportation investments.” 
  • “State DOTs are well positioned to track GHG emissions from highways and integrate that information into transportation decision making processes. The proposed GHG measure is similar and complementary to the other national measures that DOTs already use to assess performance under the [Transportation Performance Management] framework, including existing measures related to safety and system performance.”

II. The proposed Performance Measure will support improved environmental performance of the NHS and help achieve climate goals.

  • “In addition to the national policies targeting emissions reductions of 50–52% by 2030 and net-zero emissions by 2050, many states, including those represented in this letter, have also established their own emissions reductions targets, either by statute or policy. Meeting these climate commitments will require substantial cuts in pollution from transportation, the largest source of GHG emissions in the United States. The proposed measure will inform the state and local planning processes needed to help address these emissions.”
  • The letter provides numerous examples of policies and initiatives each state is already pursuing to measure and address global warming pollution from the transportation sector, emphasizing that the proposed federal measure is compatible with and complementary to what states are already doing. 

III. The proposed Performance Measure supports improved performance of the NHS by enhancing the resilience of our roads and bridges.

  • “A future with higher GHG emissions is a future with higher temperatures and greater climate-related risks to our nation’s infrastructure. Higher temperatures will result in greater sea-level rise, which will inundate more low-lying ports, coastal railways and roadways…”
  • “[E]ncouraging states to prioritize and plan programs and projects that reduce GHG emissions from transportation, the proposed rule will support improved performance of the NHS by reducing the risk of climate change-related impacts.”

IV. Reducing transportation-sector GHG emissions to levels aligned with national 2030 and 2050 commitments – and state and local emissions targets – will require a range of coordinated policy actions at the federal, state, and local levels. 

  • “We recognize that state DOTs will need to coordinate planning efforts across state agencies, federal and local government partners, external stakeholders, and others to successfully implement the proposed rule. For example, in setting targets, state DOTs will need to account for the emissions impact of a range of policies, including those related to vehicle fuel switching, tailpipe emissions, and vehicle miles traveled.” 
  • “To achieve GHG emissions reductions in line with the proposed rule and established state targets, state DOTs will need to engage within their own departments, with MPOs, and across agencies to identify and implement low-carbon investments and policies. Advancing new low-carbon transportation strategies will also require extensive engagement with public- and private-sector partners.”
  • “[W]e encourage FHWA to work closely with DOTs to understand their needs and provide technical assistance and guidance that makes it easier for state DOTs and MPOs to meet the requirements of the proposed rule.”

“As states that are working to make smart infrastructure investments and cut greenhouse gas (GHG) emissions,” write the signatory transportation secretaries and commissioners, “we thank FHWA for taking action to establish a framework for states to measure GHG emissions and set targets for reducing emissions from National Highway System roadways.” 


Press Contact: Pete Rafle, Georgetown Climate Center,, (202) 662-6672

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