The rule never took effect after federal courts ruled that the Department of Transportation lacked legal authority to enforce it.
The U.S. Department of Transportation has repealed a Biden-era rule requiring states to set targets for reducing carbon dioxide emissions from vehicles on federally funded highways, Transportation Secretary Sean Duffy announced on April 18.
The
rule, finalized in 2023 but never implemented due to legal challenges, would have required state transportation agencies and metropolitan planning organizations to track tailpipe emissions on the National Highway System and establish declining greenhouse gas targets. Duffy called the regulation an unlawful overreach that prioritized climate policy over core infrastructure needs.
“Under President Trump’s leadership, we are going to build great, big, beautiful things again,” Duffy said in a
statement. “I slashed this ridiculous climate requirement to ensure no radical political agenda gets in the way of revitalizing America’s highways.”
The move is part of a broader effort by the Trump administration to reverse
regulations introduced during the Biden administration. Officials said the rule lacked statutory authority and would have forced states to divert resources from highway and bridge projects to meet emissions targets that were not approved by Congress.
The rule never took effect after federal courts in Texas and Kentucky
ruled that the Department of Transportation lacked legal authority to enforce it. The Biden administration appealed both rulings, and the Trump administration later withdrew those appeals, leaving the rule vacated and unenforceable.
The Federal Highway Administration (FHWA) described the repeal, which was
published in the Federal Register on Friday, as a deregulatory action that aligns with court rulings in Texas and Kentucky, which found that the emissions mandate exceeded the agency’s legal authority under current transportation law. The repeal does not prohibit states from tracking emissions voluntarily.
Industry groups welcomed the change.
The American Road & Transportation Builders Association called the rule “unnecessary” and praised the administration for eliminating a mandate that “would have placed new burdens on mobility solutions.” The American Trucking Associations said the regulation would have “scrambled local priorities” and made it harder to expand highway capacity.
The Associated General Contractors of America said the rule “would have forced states to put important infrastructure projects, like road and bridge improvements, on hold.” The group said the repeal is consistent with congressional intent and will help keep freight and passenger traffic moving.
The Biden-era FHWA had proposed the rule in 2022 and stated that setting emissions targets would help states make informed investment decisions and qualify for funding under the Bipartisan Infrastructure Law.
That law allocated billions of dollars to help states fund projects like electric vehicle charging stations, carbon reduction strategies, and public transportation upgrades. FHWA leaders at the time said the rule would bring national consistency to policies already in place in 24 states and the District of Columbia.
In his announcement, Duffy said more reversals are likely as part of the president’s efforts to cut red tape and refocus the federal transportation agenda on traditional infrastructure priorities.
