In the face of the Trump administration’s hostility toward California’s Clean Air Act waivers in general, CARB withdrew its request to EPA for a waiver for the Advanced Clean Fleets (ACF) regulation on January 13, 2025. For more background on the ACF rules, see our prior client alert.
In conjunction with the withdrawal, CARB announced that it will not enforce the portions of the ACF that require a federal waiver, including those that apply to high-priority and drayage fleets. Elements of the ACF that do not require a waiver, such as the state and local government fleets portion, are unaffected by the withdrawal and will be enforced.
With this development, fleets that would have been covered by the ACF regulation are no longer required to meet its reporting and electrification requirements. CARB has said, however, that it is evaluating its next steps, meaning it may still pursue some form of regulation in the absence of a waiver. Moreover, CARB and other state regulators are expected to become more active in the carbon and climate space as the Trump EPA rolls back federal climate regulations and policies. In light of this, fleet operators should remain ready to comply with CARB’s next iteration of its clean fleet rules if and when they are announced.