On Jan. 29, 2025, U.S. Transportation Secretary Sean Duffy approved a proposed rule to rescind the Federal Highway Administration’s Greenhouse Gas Performance Measure final rule.

The proposed rescission is now under review at the Office of Information and Regulatory Affairs, the final step before it can be published in the Federal Register and take effect.

The Greenhouse Gas Performance Measure rule had already been blocked from taking effect by a court order in March 2024. On Feb. 3, 2025, the FHWA dropped its appeal of this ruling and the case was dismissed, meaning that the rule is not expected to be reinstated absent new legal action.

The final rule required that state departments of transportation and metropolitan planning organizations—the state entities responsible for transportation infrastructure construction and maintenance—measure and report GHG emissions associated with transportation. Further, state DOTs and MPOs were required to set targets for reducing carbon dioxide emission and report on progress toward these targets. The rule did not mandate particular targets, allowing states to set their own targets as long as they achieved some amount of emission reduction.

Potentially, the rule could have delayed or canceled certain transportation projects such as roadways and bridges as the agencies sought to achieve GHG emission goals.