The Environmental Protection Agency (EPA) is pushing back hard against California’s newly proposed roadside inspection requirements for heavy-duty vehicles registered out of state or abroad. On August 25, 2025, the EPA announced it intends to disapprove California’s heavy-duty Inspection & Maintenance (I/M) program, citing violations of the U.S. Constitution’s Commerce Clause and Section 110 of the Clean Air Act. The agency slammed the move as a power grab that unfairly burdens truck drivers and engine manufacturers, who it says deliver essential goods across the country. The EPA warned that these rules would drive up costs for Americans relying on trucking services and threatened, “We will not sit idly by while… they raise the cost of living on all Americans we rely on truck drivers to serve.” The proposed disapproval is set to appear in the Federal Register on August 26, triggering a 30-day public comment period.
Additionally, the EPA highlighted the recently terminated antitrust investigation into the Clean Truck Partnership—a 2023 agreement between truck makers and California regulators to adhere to state emissions standards, including Omnibus Low-NOx, Advanced Clean Fleets, and Advanced Clean Trucks, regardless of California’s legal authority being upheld. This, the EPA suggests, further exemplifies California’s overreach under the guise of climate action.
