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Regulations for Emissions from Vehicles and Engines

Final Rule: One National Program on Federal Preemption of State Fuel Economy Standards

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Rule Summary

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U.S. Department of Transportation’s National Highway Traffic Safety Administration (NHTSA) and the U.S. Environmental Protection Agency (EPA) issued a final action entitled the “One National Program Rule” to enable the federal government to provide nationwide uniform fuel economy and greenhouse gas emission standards for automobile and light duty trucks.  This action finalizes critical parts of the Safer, Affordable, Fuel-Efficient (SAFE) Vehicles Rule that was first proposed in August 2018. This action makes clear that federal law preempts state and local tailpipe greenhouse gas (GHG) emissions standards as well as zero emission vehicle (ZEV) mandates. 

In this action NHTSA is affirming that its statutory authority to set nationally applicable fuel economy standards under the express preemption provisions of the Energy Policy and Conservation Act dictates that such state and local programs are preempted.  EPA is also withdrawing the Clean Air Act preemption waiver it granted to the State of California in January 2013 as it relates to California’s GHG and ZEV programs.

Rule History

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