California, known for its commitment to environmental sustainability, has taken a groundbreaking step towards reducing greenhouse gas emissions and improving air quality. On April 28, 2023, the California Air Resources Board (CARB) unanimously adopted the Advanced Clean Fleets (ACF) regulation to transition California fleets to zero-emission medium- and heavy-duty vehicles, marking the world's first mandate to phase out gas- and diesel-powered truck sales.
The ACF rule complements the Advanced Clean Truck (ACT) regulation adopted in 2020, which set a timeline for vehicle manufacturers to phase out most vehicles powered by fossil fuels and ensure that zero-emission vehicles become available. The goal is to reach 100% zero-emission vehicles by 2045 with earlier targets for market segments such as drayage trucks, first- and last-mile delivery, garbage trucks, local buses, and utility and government vehicles.
Starting next year in 2024, under this new regulation, high-priority fleets which include large fleets and local, state, and federal government fleets will begin transitioning to zero-emission vehicles. From 2024 to 2035, the percentage of zero-emission truck sales required progressively rises.
For example, last-mile delivery and yard trucks must transition by 2035, work trucks and day cab tractors must be zero-emission by 2039, and sleeper cab tractors and specialty vehicles must be zero-emission by 2042.
CARB estimates that by 2035, 2045, and 2050, the ACT and ACF regulations will result in approximately 510,000, 1,350,000, and 1,690,000 zero-emission vehicles (ZEVs) in California, respectively.
Exemptions based on available technology are available for fleet owners. Fleets can also opt for a phased transition through the optional ZEV Milestone Phase-In program, allowing flexibility to continue using combustion-powered vehicles as needed.
To support the transition, California agencies have committed to the Zero-Emission Infrastructure Joint Agency Statement of Intent. This collaboration will plan, develop, deploy, and fund the necessary electric charging and hydrogen stations to achieve zero emissions by 2045.