United States EPA Administrator Andrew Wheeler announced on January 6 that the agency released an Advanced Notice of Proposed Rulemaking (ANPRM) to establish new, more stringent emission standards for oxides of nitrogen (NOx) and other pollutants for heavy-duty engines through its Cleaner Trucks Initiative. The EPA is seeking public input on its forthcoming rulemaking which would implement the first revisions to the NOx emissions standards for heavy-duty trucks since January 2001. Additionally, the EPA has published a fact sheet outlining its priorities and goals for the forthcoming notice of proposed rulemaking.

Stakeholders such as the American Trucking Associations (ATA), Truck and Engine Manufacturers Association (EMA), and the Association of Air Pollution Control Agencies have said that that they look forward to working the EPA to the development of an acceptable standard.