California Air Resources Board

SACRAMENTO:  Heavy-duty vehicle public fleet owners subject to California’s Advanced Clean Fleet (ACF) regulation have new flexibility in meeting the regulation’s requirements along with streamlined processes for applying for exemptions. Today’s approval of amendments to ACF by the California Air Resources Board (CARB) will help state and local fleets continue introducing zero-emission vehicles (ZEVs) to their fleets while providing clarity, certainty and flexibility in ACF’s implementation.  

The Board also voted to repeal parts of the ACF regulation applying to federal or private fleets, including requirements for drayage trucks, to reduce confusion for federal and private fleet operators. 

The amendments help satisfy the requirements of Assembly Bill 1594, which directed CARB to provide flexibility to most public agency utilities that use highly specialized vehicles in carrying out their work. Public utilities will have expanded access to several exemptions allowing the purchase of combustion engine vehicles when ZEVs are not available or do not meet the fleet’s needs. CARB also will move forward with modifications that ease the entry to ZEVs for public fleets. This includes extending the 50% ZEV purchase requirement by three years and delaying the 100% ZEV purchase requirement to 2030; extending the exemption for small fleets and designated low population counties until 2030; and ensuring all proposed compliance flexibilities apply to all government agencies, not only public agency utilities.   

“Today’s approval of amendments to ACF – a critical component in the state’s efforts to achieve emissions reductions for a healthier future for all residents – keeps California advancing towards the cleanest fleet in the nation and provides flexibilities to help ensure a smooth implementation,” said CARB Chair Liane Randolph.   

The amendments are expected to be effective before January 2027.  

Adopted in 2023, the ACF regulation set a pathway to phasing-in zero-emission medium- and heavy-duty vehicles into fleets to improve air quality and public health. As it was originally written, the regulation was projected to yield $26 billion in health savings from reduced hospitalizations, emergency room visits and respiratory illnesses. It also was projected to save fleet owners $48 billion in total operating costs through 2050. CARB withdrew its Clean Air Act waiver request for ACF because of the federal administration’s stated opposition to California’s authority to establish greenhouse gas and zero-emission standards for new motor vehicles. CARB is instead pursuing alternative means to reduce emissions from this sector. 

In addition to developing cleaner fleets through ACF, the state is also actively implementing the Clean Truck Check program aimed at promptly identifying and correcting malfunctions of heavy-duty vehicles’ emissions control systems through routine inspections.  

While trucks represent only 6% of the vehicles on California’s roads, they account for over 35% of the state’s transportation generated nitrogen oxide emissions and 25% of the state’s on-road greenhouse gas emissions. Reducing emissions from medium- and heavy-duty vehicles is a key component in the state’s efforts to meet national air quality standards.