On March 29, 2024, EPA announced new emission standards for heavy-duty vehicles for model years 2027 through 2032. The rule, Greenhouse Gas Emissions Standards for Heavy-Duty Vehicles – Phase 3, regulates heavy-duty vocational vehicles such as delivery trucks, refuse haulers, and public utility trucks and tractors such as day cabs and sleeper cabs on tractor-trailer trucks. The standards are touted by the Biden administration as the strongest ever. According to EPA, this rule will avoid approximately 1 billion metric tons of greenhouse gas emissions from 2027 through 2055.  

The new rules will be phased in gradually. EPA divided heavy-duty vocational vehicles into three categories: light, medium, and heavy. The first reduction for light and medium begins with model year 2027, whereas the first reduction for heavy begins in 2029. For tractors, day cab tractor reductions begin in 2028, while sleeper cab tractors begin reduction in 2030.

EPA described the standards as technology neutral, meaning that the standards can be met through a diverse range of technologies including advanced internal combustion engine vehicles, hybrid vehicles, and hydrogen fuel cell vehicles. While EPA described the standards as technology neutral, EPA modeled potential compliance pathways based on an increase in the use of zero-emission vehicle technologies. 

Throughout the comment process, industry groups have expressed skepticism in the ability to meet the new standards, noting the lack of infrastructure and the current state of zero-emission technology. Industry participants should carefully review the standards to ensure their compliance under the new rule.