California withdraws Advanced Clean Fleets, In-Use Locomotive regulations

16 January 2025

The California Air Resources Board (CARB) withdrew its requests for US EPA waivers for two important emission regulations: the Advanced Clean Fleets (ACF) rule and the In-Use Locomotive regulation. The CARB waiver withdrawal letters to the EPA are dated January 13, 2025—days before the incoming US administration of president Trump takes office.

In its response letters to CARB, the EPA said it is taking no further action on the respective authorization requests and considers the matter closed.

The ACT regulation, among other provisions, included a 100% ZEV requirement for all Class 2b-8 vehicles sold in California (except for authorized emergency vehicles) from 2036.

The CARB Advanced Clean Trucks (ACT) regulation, however, which introduced a mandatory percentage schedule for heavy-duty ZEV sales in California, remains in place. Under the ACT rule, in 2035, 55% of Class 2b-3 vehicles, 75% of Class 4-8 vehicles, and 40% of Class 7-8 tractors must by ZEVs.

The In-Use Locomotive Regulation would require rail operators to pay into an escrow account, which would be used to upgrade to cleaner locomotive technologies, and would establish zero-emission requirements for locomotives operating in California.

The ACF and the locomotive regulations were strongly opposed by the respective industries, who feared the high costs of compliance and disruptions throughout the US supply chains.

Source: US EPA