The California Office of Administrative Law (OAL) has approved amendments to the Advanced Clean Fleets (ACF) regulation, finalizing several important changes that affect both public- and private-sector fleet operators. The amendments became effective on September 10, 2026, when they were filed by OAL with the Secretary of State.
The changes provide greater regulatory certainty for affected fleets and clarify how portions of the regulation will be implemented going forward. The California Air Resources Board (CARB) has indicated that revised regulatory documents reflecting these changes will be available soon.
Among the approved changes is the repeal of the High-Priority Fleet and Drayage Fleet requirements, which would have required private-sector fleets to transition to zero-emission trucks on an accelerated schedule. CARB pursued the repeal following the withdrawal of its request for a federal waiver from the U.S. Environmental Protection Agency and ongoing legal challenges to the regulation, including a lawsuit brought by the California Trucking Association. CARB stated that removing these provisions would provide greater regulatory certainty for affected fleets while allowing the agency to evaluate future approaches to reducing emissions in the heavy-duty transportation sector. With these provisions formally removed, CARB would likely need to undertake a new rulemaking process to implement similar fleet purchasing mandates in the future.
CARB will continue to implement the public-sector portions of the regulation, including provisions that affect certain private contractors providing services to public agencies. Following stakeholder engagement and advocacy efforts, CARB revised its interpretation of the language to clarify that the requirements apply only to private contractors whose vehicles are specifically dispatched by a public entity. As a result, only contractors whose fleets are under the operational control of a public agency are subject to the regulation’s public fleet requirements. These clarifications reflect the collective efforts of CRTA and other industry stakeholders to help ensure the regulation is implemented as intended and to provide greater certainty for affected fleets.
CRTA will continue to monitor developments and provide updates as additional guidance and information become available.