Medium- and heavy-duty (MHD) vehicles are outsized contributors to the transportation sector’s emissions of carbon dioxide and other air pollutants. While most MHD vehicles currently run on diesel, zero-emission battery and hydrogen fuel cell options are becoming more available. Although adoption of these alternatives is not yet nearly as robust as it is in the light-duty passenger vehicle sector, a growing number of MHD use cases are conducive to electrification, including delivery vehicles, school and transit buses, regional freight trucks, drayage vehicles, and other work vehicles.

Electrifying the medium- and heavy-duty portion of the transportation sector, however, faces some unique challenges. These include higher up-front costs for vehicles and associated charging/refueling infrastructure, a lack of widespread access to charging and refueling infrastructure, strain on local electric grids, reduced cargo capacity due to the size and weight of batteries, conflicts between recharging/refueling needs and regulations on drivers’ hours of service, and the upstream emissions associated with hydrogen fuel production. At the same time, MHD vehicle electrification also presents significant opportunities. In addition to the environmental and public health benefits, MHD vehicle electrification could offer greater long-term fuel cost savings and enhanced community resilience.

Policy Recommendations:

Numerous federal and state regulations, incentives, and programs are already in place to support the electrification of the MHD vehicle fleet. These include federal emissions standards, state clean truck regulations, federal funding programs for innovation and deployment, and state rebate programs. Still, additional policy measures are necessary to overcome the range of challenges facing MHD vehicle electrification, including:

Supporting technology development and innovation: Congress should provide additional funding to support innovations in battery efficiency and to improve green hydrogen production efficiency and costs. The Department of Energy (DOE) should also conduct battery-swapping pilots for federal and commercial MHD fleets to explore cost and performance feasibility.

Expanding accessible MHD charging and refueling infrastructure: Congress and state legislatures should increase the amount of, and expand eligibility for, commercial charging/refueling infrastructure tax credits. Congress should also fund grants to enable utilities to make grid upgrades to support charging infrastructure, and the DOE should prioritize clean hydrogen development along freight corridors. In addition, federal regulators should update regulations, including on drivers’ hours of service, to accommodate charging times and other technology-specific constraints.

Accelerating vehicle deployment: The Environmental Protection Agency (EPA) and National Highway Traffic Safety Administration (NHTSA) should strengthen federal emissions standards to reach 100 percent zero-emissions MHD vehicle sales no later than 2040, and earlier where possible. Congress should also provide block grants for states and municipalities to replace government MHD vehicles with zero-emission vehicles, prioritizing high-pollution areas. To overcome potential wariness about newer technologies, the Departments of Transportation, Labor, and Education should fund and provide education, outreach, and workforce training initiatives to fleet owners, operators, drivers, and service technicians on zero-emission vehicle operation, charging management, and cost-benefit analysis.

Proactive policy at all levels is needed to accelerate the decarbonization of the medium- and heavy-duty vehicle fleet and the transition to a zero-emission transportation future.