The EPA expects the standards to accelerate the transition to clean vehicles while also tackling...

The EPA expects the standards to accelerate the transition to clean vehicles while also tackling the climate crisis.

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Model Year 2027 could bring more stringent greenhouse-gas emission standards for heavy-duty vocational vehicles, including school buses, if the Environmental Protection Agency (EPA) goes through with a new proposal.

The plan, announced April 12, calls for stronger carbon dioxide standards than applied under the HD Phase 2 Greenhouse Gas Program.

“By proposing the most ambitious pollution standards ever for cars and trucks, we are delivering on the Biden-Harris Administration’s promise to protect people and the planet, securing critical reductions in dangerous air and climate pollution and ensuring significant economic benefits like lower fuel and maintenance costs for families,” said Michael S. Regan, EPA administrator.

Overview of the Phase 3 Proposal

The heavy-duty truck standards would apply to delivery trucks, refuse haulers, dump trucks, public utility trucks, transit, shuttle, and school buses, and trucks typically used to haul freight. The proposal uses performance-based standards so that manufacturers can achieve compliance based on fleet composition.

According to a news release, net benefits of the heavy-duty proposal are projected to range between $180 to $320 billion and could avoid 1.8 billion tons of CO2 through 2055, “equivalent to eliminating all greenhouse gas emissions from the entire current U.S. transportation sector for an entire year, and deliver additional health benefits by reducing other pollutants from these vehicles."

Ben Prochazka, executive director of the Electrification Coalition, praised the proposal's potential to accelerate adoption of cleaner technologies for the country's transportation systems.

"While the timeline is ambitious and might be a challenge for some in the automotive sector, we must urgently develop robust, secure supply chains with our allies and establish U.S.-based manufacturing to electrify our cars, trucks, and buses," Prochazka said. "This move, along with the policies and programs created by the Inflation Reduction Act and Bipartisan Infrastructure Law, provides important clarity, and is another mechanism that will stimulate state and local policies and private sector investments to accelerate electrification."

An Opportunity for Feedback

Written comments may be submitted to the rulemaking docket via, docket ID No. EPA-HQ-OAR-2022-0985. Comments are due 50 days after publication in the Federal Register.

EPA plans to hold a two-day virtual public hearing the Phase 3 GHG proposal on May 2 and 3, 2023. To register to speak at the virtual hearing or attend the hearing (including those who do not intend to provide testimony) notify EPA by April 26, 2023, preferably by email to


About the author
Wes Platt

Wes Platt

Executive Editor

Wes Platt joined Bobit in 2021 as executive editor of School Bus Fleet Magazine. He writes and edits content about student transportation, school bus manufacturers and equipment, legislative issues, maintenance, fleet contracting, and school transportation technology - from classic yellow diesel buses to the latest EPA-funded electric, propane, and CNG vehicles.

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