The California Air Resources Board (CARB) has approved a series of amendments to the state’s Advanced Clean Trucks (ACT) and Zero-Emission Powertrain (ZEP) Certification regulations, aimed at preserving emissions benefits while offering truck manufacturers additional flexibility to comply with the rules.
The amendments are part of California’s broader strategy to reduce harmful emissions from medium- and heavy-duty vehicles, while also reinforcing commitments made in the Clean Truck Partnership, a 2023 agreement between CARB and the nation’s major truck manufacturers to support zero-emission vehicle (ZEV) deployment.
“The amendments approved today provide manufacturers with flexibility, and we look forward to continued collaboration with manufacturers in efforts to reduce emissions, protect public health and ensure global competitiveness as the rest of the world shifts to zero-emission technologies,” said CARB Chair Liane Randolph.
The adopted changes include several minor adjustments with no significant cost or emissions impact. Key updates include the addition of a “pooling” option to allow manufacturers to transfer surplus ZEV and near-zero emission vehicle (NZEV) credits between states that have adopted the ACT regulation. Manufacturers can also offset a portion of deficits in the Class 7-8 vehicle group with credits from Class 2b-3 or Class 4-8 ZEVs, providing more flexibility across vehicle categories.
Other amendments adjust the minimum all-electric range requirement for NZEVs in future years, increase manufacturer discretion in retiring compliance credits, and update communication protocols for ZEV connector criteria under the ZEP certification process.
Despite recent legal and political turbulence, CARB continues to advance its policies concerning vehicle emissions. Earlier this summer, President Trump signed resolutions seeking to overturn California’s waivers for its Advanced Clean Trucks, Advanced Clean Cars II, and Heavy-Duty Engine and Vehicle Omnibus rules.
In response, Governor Gavin Newsom signed an executive order directing state agencies to explore additional pathways to accelerate the deployment of zero-emission vehicles across all weight classes. Those agencies have already begun gathering public input and are expected to deliver formal recommendations to the governor in August.
