Potential benefits of the U.S. Phase 3 Greenhouse Gas Emissions Regulation for Heavy-Duty Vehicles
The revision of the U.S. Environmental Protection Agency’s greenhouse gas standards for medium- and heavy-duty vehicles is a unique opportunity to closely align emission reductions in the sector with U.S. climate goals. This study presents several possible scenarios for the standards, estimates each scenario’s potential to align with U.S. climate goals, and quantifies the associated air quality and health benefits through 2050.
The analysis finds that currently adopted regulations for medium- and heavy-duty vehicles are not sufficient to align the sector with U.S. climate commitments. Fully aligning the sector with climate goals would require a 55% zero-emission vehicle sales share in 2030, including a 40% zero-emission vehicle sales share for long-haul tractors. More stringent greenhouse gas emission reduction targets can be met by a combination of zero-emission vehicle uptake and internal combustion engine efficiency improvements. The analysis finds that cost-effective internal combustion engine vehicle improvements of up to 25% for tractors and 31% for vocational trucks can be achieved beyond 2027.
Stringent greenhouse gas standards could deliver billions of dollars in health and climate social benefits, with a large share of health benefits occurring in communities that meet environmental justice criteria. An accelerated transition to zero-emission vehicles could avoid up to $231 billion in discounted social costs of CO2. Additionally, the accelerated transition could help avoid $22.9 billion in health benefits, with 40% of these benefits occurring in communities that meet at least one environmental justice criterion.