How California (And Other States) Can Drive Demand for Clean Trucks

This post is co-authored by CLEE fellow Marie Grimm.

California’s policies to phase out polluting diesel trucks with zero-emission models took a major hit this year from the federal government. In June 2025, Congress voted to overturn federal permission for California’s zero-emission truck mandate (although this vote is now subject to litigation). In July, Congress then voted to terminate many of the tax incentives that lowered zero-emission truck costs. Furthermore, the state in January withdrew its waiver request from the EPA for its proposed mandate for major fleets to purchase zero-emission trucks — expecting that the incoming Trump administration would deny it.

Yet the the need to address truck pollution remains urgent. Medium- and heavy-duty trucks are major contributors to greenhouse gas emissions and air pollution. Although they make up only 6% of all vehicles in California, they account for 25% of the state’s on-road greenhouse gas emissions and 35% of transportation-caused nitrogen oxide emissions. They also disproportionately impact low-income communities near shipping centers and highways.

The good news is that zero-emission trucks in some market segments already rival fossil-fueled alternatives on total cost of ownership. But in the near term they are still often more expensive for many use cases. As a result, even with continued decreases in expected battery costs, demand is not yet sufficient to match the pace of the needed transition and requires near-term federal and state policy support.

To identify new state actions to increase demand for zero-emission trucks, UC Berkeley’s Center for Law, Energy and the Environment (CLEE) and the UCLA Law Emmett Institute on Climate Change and the Environment, with support from Bank of America, are today releasing the new report: Driving Demand: Solutions to Increase the Market for Heavy-Duty Zero-Emission Vehicles.

Based on an expert convening and literature review, the report outlines key barriers hindering market development and solutions to overcome these barriers and achieve the needed demand. Recommendations for the the California Legislature include:

• Create a “Clean Miles Standard” for freight, which would require shippers to meet a certain percentage of the miles their goods travel via clean technologies, like zero-emission trucks.
• Develop revenue neutral, self-funding incentive programs for heavy-duty zero-emission vehicles, in which fees on non-zero-emission vehicles fund rebates for clean vehicles.
• Provide tax credits for heavy-duty zero-emission vehicles to help offset the purchasing cost of new zero-emission heavy-duty vehicles, as well as exempt heavy-duty zero-emission vehicles from the state sales tax, or at least ensure they are taxed no more than their diesel counterparts.
• Equalize zero-emission truck registration fees to ensure that purchasers do not pay more for registration than for registering diesel trucks.

The report also contains recommendations for state agencies and ports, including:

• The California Air Resources Board could create a statewide Indirect Source Rule under the Clean Air Act, which would regulate facilities like ports and warehouses that generate pollution indirectly by attracting mobile sources of emissions like trucks and then require emission reductions from that vehicle traffic.
• The Governor’s Office and the Department of General Services could create government procurement regulations requiring purchase or lease of zero-emission trucks and direct the Department of General Services to implement and oversee them.
• The Governor’s Office of Business and Economic Development could help facilitate the aggregation of shipper demand by coordinating various efforts and groups to enhance collective truck purchasing power and aggregating shipper demand for zero-emission freight initiatives to reduce supply chain and vehicle costs.
• Ports could create incentive programs for zero-emission heavy-duty vehicles, such as by providing green lanes, preferential reservation, or reduced fees for zero-emission vehicles.

Read the full report on either the CLEE or Emmett Institute websites. This report is the latest release in the Climate Change & Business Research Initiative, a collaboration between CLEE and UCLA Law’s Emmett Institute on Climate Change & the Environment, supported by Bank of America since 2009.

To learn more about these and other recommendations contained in the report, please register for our upcoming CLEE and Emmett Institute webinar on Tuesday, January 13 from 2-3pm PT. The webinar will feature a keynote by California Energy Commissioner Nancy Skinner, as well as a panel discussion with Ray Minjares of the International Council on Clean Transportation and Adam Browning from Forum Mobility.