In an effort to regulate and reduce emissions from medium- and heavy-duty vehicles in Washington, the Washington State Department of Ecology adopted the Advanced Clean Trucks Rule to require truck makers to sell an increasing number of clean, zero-emission vehicles in the state.

The department also adopted the Zero Emission Vehicle Program, which directs light-duty vehicle manufacturers to increasingly sell zero emission vehicles in Washington. Starting in 2024, the program will result in zero emission vehicles making up 8% of all light-duty vehicle sales, according to the department.

Earlier this month, Oregon became the first state to adopt the ACT Rule after California. All West Coast states now have regulations in place requiring the sale of clean, zero-emission light-, medium- and heavy-duty vehicles.

A representative of the Washington Trucking Association said that while the association supports continous improvement in clean diesel technologies, adopting rules developed based on California's pollution issues and economic conditions is not right for Washington. There is not a one size fits all solution, WTA President and CEO Sheri Call told HDT.

"Washington doesn't currently have money available to incentivize widespread adoption of heavy-duty zero emission vehicles," Call said. "Incentives will be necessary to help bring truck costs in line with diesel fueled vehicles. California has had a cap and invest program in place for several years, many incentive programs have been developed around these funds to reach carbon reduction goals. Washington is just getting started in the rule making process."

Futhermore, Call says the state lacks infrastructure to charge and service zero emission vehicles.

Four East Coast states—Maine, Massachusetts, New Jersey, and New York—are also considering adopting the ACT rule this year, according to a joint press release from Climate Solutions and the Natural Resources Defense Council.

Together these seven states contain more than 20% of the national fleet of medium- and heavy-duty trucks, according to Federal Highway Administration data sited in the joint press release. 

[Editor's Note: This article was updated Dec. 2 at 9 a.m. to include comment from the Washington Trucking Assocaition.]