Abstract:

The study 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.