EPA publishes final rule on GHG standards for heavy-duty vehicles

April 1, 2024
The rule, which covers transit and shuttle buses, will phase in stronger greenhouse gas standards starting with model year 2027 vehicles.

The Environmental Protection Agency (EPA) has published the final rule, Greenhouse Gas Emissions Standards for Heavy-Duty Vehicles - Phase 3, which the agency says will reduce air pollution by avoiding 1 billion tons of greenhouse gas emissions. 

The new rule, which builds on the EPA’s “Phase 2” rule established in 2016, will phase in standards for heavy-duty vehicles, including transit and shuttle buses over Model Years (MY) 2027 through 2032. EPA says the standards provide “more time and flexibility for manufacturers to develop, scale and deploy clean heavy-duty vehicle technologies.” 

For heavy-duty transit vehicles, the Phase 3 standards in the final rule are 13 percent stronger than Phase 2 starting in MY 2029 and increase to 30 percent stronger in MY 2032. EPA says standards are technology-neutral and performance-based, allowing each manufacturer to choose what set of emissions control technologies is best suited for them and the needs of their customers. The agency also explained the standards can be met through a variety of vehicle models, including advanced internal combustion engine vehicles, hybrid vehicles, plug-in hybrid electric vehicles, battery electric vehicles and hydrogen fuel cell vehicles. 

“In finalizing these emissions standards for heavy-duty vehicles like trucks and buses, EPA is significantly cutting pollution from the hardest working vehicles on the road,” said EPA Administrator Michael S. Regan. “Building on our recently finalized rule for light- and medium-duty vehicles, EPA’s strong and durable vehicle standards respond to the urgency of the climate crisis by making deep cuts in emissions from the transportation sector.”

EPA says the standards will provide $13 billion in annualized net social benefits related to public health, the climate and savings for fleet owners and operators. 

The final rule includes analysis of costs under the new standards, including costs per mile, as well as maintenance and repair costs. EPA estimates fuel cost per mile for MY 2032 vehicles from calendar years 2023 to 2055 will range from 20.2 cents/mile to 38.2 cents/mile for diesel urban buses, 8.5 cents/mile to 16 cents/mile for electric buses and 23.2 cents/mile to 43.9 cents/mile for compressed natural gas (CNG) buses.

EPA’s analysis estimates the maintenance and repair costs associated with heavy-duty battery electric vehicles and fuel cell electric vehicles will be lower than maintenance and repair costs associated with comparable internal combustion engine vehicles. EPA estimates the maintenance and repair cost per mile for the same model years as above will range from 13.6 cents/mile to 29.9 cents/mile for diesel and CNG buses and 9.7 cents/mile to 21.2 cents/mile for electric buses.

“This regulation will spur investment and innovation that will result in accelerated growth of the domestic zero- emission commercial vehicle industry. In the long term, this regulation will create and protect jobs while making the air cleaner and healthier for all,” said John Boesel, CEO of CALSTART. 

“The EPA’s emission standards for heavy-duty vehicles will help the public leverage economic and climate benefits of expanded access to cleaner vehicles,” said Abigail Campbell Singer, head of climate and infrastructure policy, government affairs, Siemens USA. “As a business at the forefront of eMobility solutions, Siemens applauds the finalization of this standard as it will set clear expectations for the pace of emissions reduction from large vehicles in the coming years, providing predictability for manufacturers, companies, fleet operators and policymakers alike.”

The American Bus Association (ABA) issued a statement, noting its commitment to “a cleaner environment” and its support of “appropriate climate initiatives that gradually move the United States in that direction.” However, the association sees the final rule as a mandate to rapidly shift to electric vehicles. 

“This forced march towards electric vehicles will result in a significant increase in equipment costs, potentially doubling them. Moreover, the current lack of infrastructure and limited electric capacity make this transition impractical and financially burdensome for the industry and consumers,” said ABA CEO Peter J. Pantuso. “The ABA firmly believes that a realistic and gradual approach is necessary to ensure a successful transition to electric vehicles. Rushing this process without adequate infrastructure and electric capacity will only burden the end user, the consumer and the taxpayer with increased costs. The ABA urges policymakers to consider the long-term implications and feasibility of such a transition, emphasizing the need for a comprehensive plan that addresses the challenges associated with electric vehicle adoption.”

The EPA’s final rule for Phase 3 greenhouse gas emissions can be found on EPA’s website

About the Author

Mischa Wanek-Libman | Editor in Chief

Mischa Wanek-Libman serves as editor in chief of Mass Transit magazine. She is responsible for developing and maintaining the magazine’s editorial direction and is based in the western suburbs of Chicago.

Wanek-Libman has spent more than 20 years covering transportation issues including construction projects and engineering challenges for various commuter railroads and transit agencies. She has been recognized for editorial excellence through her individual work, as well as for collaborative content. 

She is an active member of the American Public Transportation Association's Marketing and Communications Committee and serves as a Board Observer on the National Railroad Construction and Maintenance Association (NRC) Board of Directors.  

She is a graduate of Drake University, where she earned a Bachelor of Arts degree in Journalism and Mass Communication with a major in magazine journalism and a minor in business management.