Regulations for Smog, Soot, and Other Air Pollution from Commercial Trucks & Buses

• Overview
• List of related regulations

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Overview

On March 20, 2024, EPA issued new, more ambitious standards to further reduce harmful air pollutant emissions from light-duty and medium-duty vehicles starting with model year 2027. The final rule builds upon EPA’s final standards for federal greenhouse gas emissions standards for passenger cars and light trucks for model years 2023 through 2026 and leverages advances in clean car technology to unlock benefits to Americans ranging from improving public health through reducing smog- and soot-forming pollution from vehicles, to reducing climate pollution, to saving drivers money through reduced fuel and maintenance costs. The standards will phase in over model years 2027 through 2032.

• Final Rule: Multi-Pollutant Emissions Standards for Model Years 2027 and Later Light-Duty and Medium-Duty Vehicles

Clean Trucks Plan

On August 5, 2021, EPA announced plans to reduce greenhouse gas emissions and other harmful air pollutants from heavy-duty trucks through a series of rulemakings over the next three years. The first rulemaking of this Clean Trucks Plan was the final rule, Control of Air Pollution from New Motor Vehicles: Heavy-Duty Engine and Vehicles Standards, signed on December 20, 2022 (link below). Two additional rulemakings, the Phase 3 greenhouse gas rule for heavy-duty engines (link below) and the rule for multi-pollutant emissions standards for light-duty and medium-duty vehicles (link above), were signed in March 2024. With the culmination of these three rulemaking actions, the Clean Trucks Plan is now complete.

• Clean Trucks Plan.
• Final Rule: Greenhouse Gas Emissions Standards for Heavy-Duty Vehicles - Phase 3.
• Final Rule: Multi-Pollutant Emissions Standards for Model Years 2027 and Later Light-Duty and Medium-Duty Vehicles.
• Final Rule: Control of Air Pollution from New Motor Vehicles: Heavy-Duty Engine and Vehicle Standards.

List of Related Regulations

Below is a list of all regulations related to smog, soot, and other air pollution from commercial trucks and buses.

• Rule summaries;
• Regulatory impact analyses;
• Comment summaries;
• Rule histories; and
• Fact sheets.*

*Note: Rule-related materials vary by rule.

Regulation Title	Regulation Date (Year/Month)
Final Rule: Greenhouse Gas Emissions Standards for Heavy-Duty Vehicles – Phase 3	2024/04
Final Rule: Multi-Pollutant Emissions Standards for Model Years 2027 and Later Light-Duty and Medium-Duty Vehicles	2024/03
Proposed Rule: Multi-Pollutant Emissions Standards for Model Years 2027 and Later Light-Duty and Medium-Duty Vehicles	2023/04
Final Rule and Related Materials for Control of Air Pollution from New Motor Vehicles: Heavy-Duty Engine and Vehicle Standards	2022/12
Final Rule: Improvements for Heavy-Duty Engine and Vehicle Test Procedures	2021/06
Advance Notice of Proposed Rule: Control of Air Pollution from New Motor Vehicles: Heavy-Duty Engine Standards	2020/01
Final Rule for Control of Air Pollution From New Motor Vehicles and New Motor Vehicle Engines; Non-Conformance Penalties for 2004 and later Model Year Emission Standards for Heavy-Duty Diesel Engines and Heavy-Duty Diesel Vehicles	2002/08
Amendments Related to Tier 3 Motor Vehicle Emission and Fuel Standards, Nonroad Engine and Equipment Programs, and MARPOL Annex VI Implementation	2015/05
Final Rule for Emergency Vehicle Rule—SCR Maintenance and Regulatory Flexibility for Nonroad Equipment	2014/08
Direct Final Rule for Heavy-Duty Highway Program: Revisions for Emergency Vehicles	2012/06
Direct Final Rule for In-Use Testing for Heavy-Duty Diesel Engines and Vehicles; Emission Measurement Accuracy Margins for Portable Emission Measurement Systems and Program Revisions	2008/03
Final Rule for Control of Air Pollution From New Motor Vehicles and New Motor Vehicle Engines; Regulations Requiring Onboard Diagnostic Systems on 2010 and Later Heavy-Duty Engines Used in Highway Applications Over 14,000 Pounds	2009/02
Final Rule for Control of Emissions of Air Pollution From New Motor Vehicles: In-Use Testing for Heavy-Duty Diesel Engines and Vehicles	2005/06
Direct Final Rule for Amendments to Regulations for Heavy-Duty Diesel Engines	2006/08
Final Rule for Control of Emissions of Air Pollution from 2004 and Later Model Year Heavy-Duty Highway Engines and Vehicles; Revision of Light-Duty On-Board Diagnostics Requirements	2000/10
Final Rule for Control of Emissions of Air Pollution From Highway Heavy-Duty Engines	1997/10
Direct Final Rule for Revisions to In-Use Testing for Heavy-Duty Diesel Engines and Vehicles; Emissions Measurement and Instrumentation; Not-to-Exceed Emission Standards; and Technical Amendments for Off-Highway Engines	2010/11
Final Rule for Modification of Federal Onboard Diagnostic Regulations for: Light-Duty Vehicles, Light-Duty Trucks, Medium-Duty Passenger Vehicles, Complete Heavy-Duty Vehicles and Engines Intended for Use in Heavy-Duty Vehicles Weighing 14,000 Pounds GVWR	2005/10
Direct Final Rule for Control of Air Pollution From New Motor Vehicles; Revisions to Motor Vehicle Diesel Fuel Sulfur Transition Provisions; and Technical Amendments to the Highway Diesel, Nonroad Diesel, and Tier 2 Gasoline Programs	2005/11
Final Rule for Control of Air Pollution from Motor Vehicles: Tier 3 Motor Vehicle Emission and Fuel Standards	2014/04
Final Rule for Control of Air Pollution from New Motor Vehicles: Heavy-Duty Engine and Vehicle Standards and Highway Diesel Fuel Sulfur Control Requirements	2001/01
Final Rule for Clean Alternative Fuel Vehicle and Engine Conversions	2011/04
Final Rule for Emission Durability Procedures for New Light-Duty Vehicles, Light-Duty Trucks and Heavy-Duty Vehicles	2006/01
Final Rule for Nonconformance Penalties for On-Highway Heavy-Duty Diesel Engines	2012/09
Final Rule for Greenhouse Gas Emissions Standards and Fuel Efficiency Standards for Medium- and Heavy-Duty Engines and Vehicles	2011/09
Final Rule for on Ozone Transport Commission; Low Emission Vehicle Program for the Northeast Ozone Transport Region	1995/01