9.2. Advanced Clean Fleets

In response to the Governor’s Executive Order N-79-20 (Governor of California, 2020), CARB has proposed the Advanced Clean Fleets (ACF) regulation to accelerate the use of zero-emission medium- and heavy-duty trucks through establishing fleet turnover requirements. The regulation was approved by the California Office of Administrative Law (OAL) in October 2023. However, later in January 2025, California withdrew the request for a waiver to add the ACF regulation to its emissions control program. Therefore, EMFAC2025 excludes the high priority fleets and drayage trucks requirements and only reflects the impact of the State and local government fleet turnover requirements, which do not require a federal waiver or authorization.

9.2.1. State and Local Government Fleet Requirements

Staff applied the ACF requirements to the population and VMT of state and local government fleets. The inventory for state and local government fleets includes Class 2b-8 heavy-duty trucks categorized under EMFAC public fleet classifications, buses, and Class 8 solid waste collection vehicles (SWCV) with exempt license plates, which were identified using the California Department of Motor Vehicles (DMV) registration database. To reflect ACF turnover requirements for state and local government fleets, staff assumed that 50% of model year 2024–2026 vehicles mentioned above are ZEVs in each calendar year. As mandated by the ACF regulation, vehicles operating in low-population counties, which generally have fewer than 125,000 residents, were exempted from this phase (CARB, 2022). For model year 2027 and newer vehicles, 100% are assumed to be ZEVs. The ZEV populations for non-public vehicle categories remain unaffected by these requirements.