The American Trucking Associations has asked the U.S. Environmental Protection Agency to reevaluate existing heavy-duty NOx standards.

“We remain concerned that the heavy-duty NOₓ rule imposes significant burdens at a time when the trucking industry continues to contend with a prolonged freight recession and inflationary pressures,” said ATA President and CEO Chris Spear.  

Spear said in a letter to Administrator Lee Zeldin that new emission control technologies required on model year 2027 trucks are unproven, and the trucking industry is concerned that a premature rollout will disrupt the ability to efficiently move freight. 

ATA recommended that EPA grant non-conformance penalties to manufacturers to give them additional time to conduct real-world testing on new emission control systems. It also wants EPA to consider expanding credit life, credit trading, and credit use across different vehicle classes.

Earlier this month, President Donald Trump formally rescinded the 2009 federal finding that greenhouse gases endanger public health. The finding has served as the legal foundation for regulating emissions from motor vehicles and other pollution sources. Trucking industry groups were largely supportive of this decision. 

Last year, EPA said it would move forward with the 2027 timeline for the heavy-duty NOx rule, but said it planned some modifications.