Policy Driving Changes

2025

Washington's Advanced Clean Trucks (ACT) rule requires manufacturers to sell more zero-emission trucks and buses in the state. The rule applies to medium- and heavy-duty vehicles, including Class 2b through Class 8.

How does the rule work?

• The percentage of zero-emission vehicles sold must increase each year, starting with model year 2025.
• The rule applies to all-electric and fuel cell electric vehicles.
• The rule aims to reduce emissions and improve air quality.

What are the goals of the rule?

• By 2030, nearly 30% of medium- and heavy-duty vehicle sales in Washington will be zero-emission trucks.
• By 2035, nearly 60% of medium- and heavy-duty vehicle sales in Washington will be zero-emission trucks.
• By 2035, all new light-duty vehicles sold in Washington must meet zero-emission standards.

June 2025 Update — 2025 Congressional Review Act (CRA)

Passed in June by both chambers of Congress, the CRA resolutions formally revoke EPA's waivers and block enforcement of California's Advanced Clean Trucks (ACT), Low NOx Omnibus, and Advanced Clean Cars II regulations, impacting the ability of Section 177 states to enforce these rules. The three resolutions were signed into law by President Trump on June 12, 2025.

Washington State Department of Ecology's response to the rollback of the rules can be found here [PDF].

Rulemaking was underway at the time the CRA's were passed; Ecology is proceeding with rule changes and closed a related open public comment period on July 3, 2025. WTA's comments on the rule changes are available here.

2023

The Climate Commitment Act is enacted in Washington state.

2022

On Jan. 6, 2022, six states, including Oregon and Washington, followed California in approving the Advanced Clean Truck rule, requiring a growing percentage of all medium- and heavy-duty trucks sold to be zero-emission starting in 2025/2026. 

By law, manufacturers are required to increase their zero-emission truck sales in those states to 30% to 50% by 2030, and 40% to 75% by 2035.

2021

In 2021, the Legislature approved the Climate Commitment Act to adopt a cap and invest program aimed at curbing carbon emissions. The clean fuel standard was also adopted, which established RCW 70A.535. The immediate impact was a surge in Washington fuel prices, starting at $.55/CPG.

2020

The Washington State Legislature changed the Greenhouse Gas (GHG) emission levels, adopting former Gov. Gregoire’s goals and making them more stringent. The updated limits (RCW 70A-45-020) are revised to 45% below 1990 levels by 2030, 70% below 1990 levels by 2040, and 95% below 1990 levels by 2050.  

On July 14, 2020, 15 states and the District of Columbia announced a joint memorandum of understanding (MOU), committing to work collaboratively to advance and accelerate the market for electric medium- and heavy-duty vehicles. The goal is to ensure that 100 percent of all new medium- and heavy-duty vehicle sales be zero emission by 2050 with an interim target of 30 percent zero-emission vehicle sales by 2030. 

States signing the MOU are: California, Connecticut, Colorado, Hawaii, Maine, Maryland, Massachusetts, New Jersey, New York, North Carolina, Oregon, Pennsylvania, Rhode Island, Vermont, and Washington.

The Legislature also adopted the Motor Vehicle Emission Standards – Zero-Emission Vehicles law (RCW 70A.30.010), adopting California’s emission standards and creating new requirements to gradually increase the number of new zero-emission vehicles (ZEV) sold in Washington. All new vehicles must meet the ZEV standard starting in 2035. The program specifically spells out new low-emission vehicle requirements for medium- and heavy-duty trucks.

2019

The Washington State Legislature passed the Clean Energy Transformation Act (CETA) aimed at decarbonizing Washington’s energy sector by 2045.

2013

In October 2013,  Gov. Jay Inslee signed the Pacific Coast Collaborative, committing Washington along with the entire West Coast, to lead on climate policy by putting in place a price on greenhouse gas pollution and mandating use of cleaner-burning fuels.

Inslee also established the Climate Legislative Executive Working (CLEW) Group in an attempt to bring together different perspectives on climate issues. This triggered subsequent legislative debates over aggressive climate policy proposals.

2007

Gov. Christine Gregoire established GHG reduction goals in February 2007 with Executive Order 07-02, setting the wheels in motion for future action on the “Washington Climate Change Challenge.”