It’s Time To Submit Your First Report to CARB

Under the requirements of the California Air Resources Board’s (CARB) Advanced Clean Fleets (ACF) regulation, California public agencies are required to submit their initial compliance reports no later than April 1, 2024. Reports are submitted electronically through the Truck Regulation Upload, Compliance and Reporting System (TRUCRS). To support users CARB has hosted a webinar (copy of slides) and provided other resources, including a handbook and FAQ / Fact Sheet. This initial report consists mostly of agency information, key contact information, and vehicle attributes for medium- and-heavy duty (MHD) vehicles currently in agencies’ fleets, which will form the baseline for determining future compliance with the regulation.

An Important Consideration: Default vs. Milestone Compliance Options

An important element to the report is the opportunity presented to the agency to choose between the default and alternative milestone compliance options. Under the default compliance option, starting January 1, 2024, 50% of MHD vehicle purchases in each calendar year must be zero-emission vehicles (ZEVs). Starting in 2027, 100% of vehicle MHD purchases must be ZEVs.

Default Compliance Option – % of MHD Vehicle Purchases

2024 2025 2026 2027 & beyond
Portion of Annual MHD Purchases 50% 50% 50% 100%

Alternatively, agencies may choose the Milestone Option which de-links the obligation to integrate ZEVs from the decision to purchase new vehicles, and instead, establishes a commitment to convert portions of the fleet (in three categories or “groups”) by target years specified by the Air Resources Board.

Alternative Milestone Compliance Option – % of Total Vehicle Fleet

Milestone Group 10% 25% 50% 75% 100%
G1 box trucks, vans, buses with two axles, and yard tractors 2025 2028 2031 2033 2035 onward
G2 pickup trucks, work trucks, day cab tractors, buses with three axles 2027 2030 2033 2036 2039 onward
G3 specialty vehicles, sleeper cab tractors 2030 2033 2036 2039 2042 onward

It is important to note that, per the regulation, once an agency elects to the milestone compliance option, the choice becomes permanent.  In almost every case that we’ve studied on behalf of our clients, we’ve found that the default compliance option presented a slower transition to ZEVs when compared to the milestone option, and provided the greatest amount of flexibility.

TerraVerde Is Here To Help

If you’re agency is looking for help submitting your initial compliance report and otherwise developing a strategy for complying with the Clean Fleets regulation, TerraVerde Energy is here to help. As independent advisors, we’re working with a broad array of clients in developing their ACF compliance plans including:

  • Developing vehicle retirement schedules
  • Comparing default vs. milestone compliance options
  • Exploring ACF exemption opportunities
  • Determining infrastructure requirements
  • Evaluating incentive funding opportunities
  • Analyzing total cost of ownership implications of this ZEV transition

If your team needs help, reach out to David Burdick at

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