State and Local Policy Database

Tailpipe Emission Standards

In 2004, the California Air Resources Board (CARB) adopted a rule requiring automakers to begin in the 2009 model year (MY) to phase in lower-emitting cars and trucks that will collectively emit 22% fewer greenhouse gases than 2002 vehicles in MY 2012 and 30% fewer in MY 2016. A suite of other states opted to sign on to California's more stringent standards. In 2012, CARB adopted new GHG standards for model years 2017 to 2025. Federal standards were subsequently finalized, bringing nationwide standards in line with California standards. However, California has, in addition, and updated zero-emission vehicle program that requires increasing production of plug-in and fuel-cell vehicles from 2018 to 2025. The GHG reductions are expected to be achieved largely, though not entirely, through improved vehicle efficiency, so these standards are in effect energy efficiency policies. Several technologies stand out as providing significant, cost-effective reductions in emissions. Among others, these include the optimization of valve operation, turbocharging, improved multi-speed transmissions, and improved air conditioning systems.

No policy in place or proposed.

Last Reviewed: July 2019

No policy in place or proposed.

Last Reviewed: July 2019

Arizona has no policy in place or proposed.

Last Reviewed: July 2019

No policy in place or proposed.

Last Reviewed: July 2019

Light-duty vehicles:

The 2002 passage of the Pavley Bill in California was the first time that a law in the United States addressed the issue of greenhouse gas emissions from cars and light trucks. In 2004, California adopted a new set of vehicle emission standards to implement the Pavley law. The regulations require automakers to produce vehicles that will, on average, reduce greenhouse gas emissions by about 30% from 2002 levels by 2016. Increased efficiency through the use of improved vehicle technology is expected to be the primary method for obtaining these reductions. Several other states have adopted California’s emissions program. California’s vehicle emission standards were harmonized with the federal fuel economy and greenhouse gas programs upon the adoption of new, more stringent federal fuel economy standards in April 2010 for model years 2012-2016.

In 2012, the California Air Resources Board adopted new GHG standards for model years 2017 to 2025 calling for a fleet-wide average increase in stringency of between 4% and 5% per year over those years. In 2012, California also updated the zero-emission vehicle (ZEV) program that requires increasing production of plug-in hybrid, battery electric, and fuel-cell electric vehicles from 2018 to 2025.

In 2016, CARB jointly published a draft Technical Assessment Report (TAR) with the U.S. EPA and NHTSA, conveying an updated cost and technology feasibility for the current standards. In January 2017, the U.S. EPA and CARB released reports finalizing their reviews and concluded the current standards remain feasible. In April 2018, the U.S. EPA issued a revised Final Determination announcing their plans to re-open the national vehicle standards and California, along with 16 other states, have filed a lawsuit opposing that action.

Heavy-duty vehicles:

In 2008, California adopted new GHG regulations to reduce emissions through the fuel efficiency improvement of tractor-trailers. Between 2010 and 2020, tractor-trailers are subject to stringent fuel economy regulations.

In 2018, CARB adopted the Innovative Clean Transit Regulation, requiring all public transit agencies to gradually transition to a 100 percent zero-emission bus fleet. Recently, CARB proposed the Zero-Emission Regulation, which would require private and public airport shuttle fleet owners to transition their fleet to zero-emission shuttles. In addition, CARB developed the Advanced Clean Truck proposal to reduce GHG emissions by accelerating the first wave of zero-emission trucks and fostering a self-sustaining market. CARB is also in the process of developing proposals for a number of new measures that will further advance the commercialization of zero- and near zero‑emission technologies. The Zero‑Emission Powertrain Certification will support current and future advanced‑technology measures applicable to medium‑duty vehicles, heavy‑duty vehicles, and off‑road equipment. This will ensure that zero‑emission technologies deployed are able to meet the reliability and performance expectations of California fleets.

Last Reviewed: July 2019

On November 16, 2018, Colorado adopted a version of California’s low emission vehicle (LEV) standards for new light-duty and medium-duty motor vehicles sold in Colorado to take effect in the 2022 model year. The standards commit Colorado to increasingly stringent fuel efficiency standards through model year 2025.

The State of Colorado is also exploring approaches to a proposed zero emission vehicle (ZEV) standard that would impose sales quotas on vehicle manufacturers, thus increasing the percentage of zero emission vehicles in Colorado. Colorado's Air Quality Control Commission will consider a Request for Hearing on a Colorado ZEV Rule on May 10, 2019. More information here: https://www.colorado.gov/pacific/cdphe/zero-emission-vehicle-mandate-proposal.

Last Reviewed: July 2019

Connecticut adopted California’s Low-Emission Vehicle Program in 2005, committing to reducing criteria and greenhouse gas emissions for new vehicles through 2025. The state has also adopted California’s Zero Emission Vehicle (ZEV) program, which requires increasing production of plug-in hybrid, battery electric, and fuel-cell vehicles from 2018 to 2025 with the goal of commercializing advanced vehicle technologies that will reduce emissions and improve energy diversification in the transportation sector.

Last Reviewed: July 2019

Delaware adopted California's clean car program in December 2010.

Last Reviewed: July 2019

The District adopted the Clean Cars Act of 2008, which adopts the California emission standards and compliance requirements for vehicles of model year 2012 and thereafter. The California standards will require all cars and light trucks sold to average more than 50 miles per gallon by 2025. On May 2, 2018, Mayor Muriel Bowser issued Executive Order 2018-044, which charged the Department of Energy and Environment with implementing and enforcing the Clean Cars Act of 2008.

Last Reviewed: July 2019

No policy in place or proposed.

Last Reviewed: July 2019

No policy in place or proposed.

Last Reviewed: July 2019

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Last Reviewed: July 2019

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Last Reviewed: July 2019

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Last Reviewed: July 2019

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Last Reviewed: July 2019

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Last Reviewed: July 2019

No policy in place or proposed.

Last Reviewed: July 2019

No policy in place or proposed.

Last Reviewed: July 2019

No policy in place or proposed.

Last Reviewed: July 2019

Maine adopted California’s Low-Emission Vehicle Program in 2005, committing to a 30% reduction in average new vehicle greenhouse gas emissions from 2002 levels by 2016. The state has also adopted California's Zero-Emission Vehicle (ZEV) program, which requires increasing production of plug-in hybrid, battery electric, and fuel-cell vehicles from 2018 to 2025. 

Last Reviewed: July 2019

On April 24th 2007, Governor Martin O’Malley signed the Clean Cars bill into law in Maryland committing to a 30% reduction in average new vehicle greenhouse gas emissions from 2002 levels by 2016. The state has also adopted California's Zero-Emission Vehicle (ZEV) program, which requires increasing production of plug-in hybrid, battery electric, and fuel-cell vehicles from 2018 to 2025. 

Last Reviewed: July 2019

Massachusetts adopted California’s Low-Emission Vehicle Program in 2006, committing to a 30% reduction in average new vehicle greenhouse gas emissions from 2002 levels by 2016. The state has also adopted California's Zero-Emission Vehicle (ZEV) program, which requires increasing production of plug-in hybrid, battery electric, and fuel-cell vehicles from 2018 to 2025. 

Last Reviewed: July 2019

No policy in place or proposed.

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Last Reviewed: July 2019

No policy in place or proposed.

Last Reviewed: August 2019

In January 2006, New Jersey adopted rules to implement the California Low Emission Vehicle (LEV) program beginning in 2009. These rules implement the Air Pollution Control Act provisions at N.J.S.A. 26:2C-8.15, which require the Department to promulgate rules to implement the California LEV program in New Jersey. The New Jersey program contains three components: vehicle emission standards, fleet wide emission requirements, and a Zero Emission Vehicle (ZEV) sales requirement. The rules will require automakers to reduce fleet-wide greenhouse gas emissions from the vehicles they sell in New Jersey 30% by 2016. The state has also adopted California's Zero-Emission Vehicle (ZEV) program, which requires increasing production of plug-in hybrid, battery electric, and fuel-cell vehicles from 2018 to 2025.

On April 3rd, 2018, Governor Murphy reaffirmed New Jersey’s support for federal fuel emissions standards and signed a multi-state agreement on clean vehicles. Furthermore, in December 2018, New Jersey committed to working with Northeast and Mid-Atlantic states in designing a new regional low-carbon transportation policy proposal that will reduce greenhouse gas emissions from the transportation sector. The Transportation and Climate Initiative (TCI) recognizes that a regional low-carbon transportation policy will spur policies and programs to reduce carbon emissions, improve air quality, help communities become more resilient to extreme weather, spur economic growth, and address the disproportionate burdens of climate change on environmental justice communities.

Last Reviewed: July 2019

No policy in place or proposed.

Last Reviewed: July 2019

New York adopted California's Low-Emission Vehicle Program in 2005, committing to a 30% reduction in average new vehicle greenhouse gases from 2002 levels by 2016. The state has also adopted a Zero-Emission Vehicle (ZEV) program, which requires increasing production of plug-in hybrid, battery electric, and fuel-cell vehicles from 2018 to 2025. 

Last Reviewed: July 2019

No policy in place or proposed.

Last Reviewed: July 2019

No policy in place or proposed.

Last Updated: July 2017

No policy in place or proposed.

Last Reviewed: July 2019

No policy in place or proposed.

Last Reviewed: July 2019

Oregon adopted California’s Low-Emission Vehicle Program in 2006, committing to a 30% reduction in average new vehicle greenhouse gas emissions from 2002 levels by 2016. The state has also adopted California's Zero-Emission Vehicle (ZEV) program, which requires increasing production of plug-in hybrid, battery electric, and fuel-cell vehicles from 2018 to 2025. 

Last Reviewed: July 2019

Pennsylvania adopted California’s Low-Emission Vehicle Program in 1998. The California standards went into effect in 2006 with Pennsylvania committing to a 30% reduction in average new vehicle greenhouse gas emissions from 2002 levels by 2016.

Last Reviewed: July 2019

Rhode Island adopted California’s Low-Emission Vehicle Program in 2005, committing to a 30% reduction in average new vehicle greenhouse gas emissions from 2002 levels by 2016. The state has also adopted California's Zero-Emission Vehicle (ZEV) program, which requires increasing production of plug-in hybrid, battery electric, and fuel-cell vehicles from 2018 to 2025. 

Last Reviewed: July 2019

No policy in place or proposed.

Last Reviewed: July 2019

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No policy in place or proposed.

Last Reviewed: July 2019

Vermont adopted California’s Low-Emission Vehicle Program in 2005, committing to a 30% reduction in average new vehicle greenhouse gas emissions from 2002 levels by 2016. The state has also adopted California's Zero-Emission Vehicle (ZEV) program, which requires increasing production of plug-in hybrid, battery electric, and fuel-cell vehicles from 2018 to 2025. 

Last Reviewed: July 2019

No policy in place or proposed.

Last Reviewed: July 2019

Washington adopted California’s Low-Emission Vehicle Program in 2005, committing to a 30% reduction in average new vehicle greenhouse gas emissions from 2002 levels by 2016.

Last Reviewed: July 2019

No policy in place or proposed.

Last Reviewed: July 2019

No policy in place or proposed.

Last Reviewed: July 2019

No policy in place or proposed.

Last Reviewed: July 2019