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Regulations for Emissions from Vehicles and Engines

Cleaner Trucks Initiative

Initiative Summary

On November 13, 2018, EPA announced the Cleaner Trucks Initiative (CTI), a future rulemaking to update standards for nitrogen oxide (NOx) emissions from highway heavy-duty trucks and engines. Over the last decade, NOx emissions in the U.S. have dropped by more than 40 percent. Nonetheless, EPA expects that heavy-duty trucks will be responsible for one-third of NOx emissions from transportation in 2025. Updating these standards will result in NOx reductions from mobile sources and could be one important way that allows areas across the U.S. to meet National Ambient Air Quality Standards for ozone and particulate matter. Updating the standards will also offer opportunities to reduce regulatory burden through smarter program design.

EPA last revised NOx standards for onroad heavy-duty trucks and buses in January 2001.


This action follows petitions for a rulemaking on this issue from over 20 organizations including state and local air agencies from across the country. More information on the petitions and EPA's response can be found here.

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