Transportation Department, National Highway Traffic Safety Administration
The National Highway Traffic Safety Administration is issuing this interpretive rule regarding the scope of its authority to set fuel economy standards for commercial medium- and heavy-duty on-highway vehicles and work trucks. This rule describes NHTSA's authority to set vehicle standards, which does not include the authority to set separate standards for engines. NHTSA will review its existing standards applicable to commercial medium- and heavy-duty on-highway vehicles and work trucks for consistency with this interpretation in a separate rulemaking. Pending the rulemaking process, NHTSA will exercise its enforcement authority with regard to affected standards in accordance with the interpretation set forth in this rule.
Document Headings Document headings vary by document type but may contain the following: the agency or agencies that issued and signed a document the number of the CFR title and the number of each part the document amends, proposes to amend, or is directly related to the agency docket number / agency internal file number the RIN which identifies each regulatory action listed in the Unified Agenda of Federal Regulatory and Deregulatory Actions See the Document Drafting Handbook for more details. Department of Transportation National Highway Traffic Safety Administration 49 CFR Parts 523, 534, and 535 [Docket No. NHTSA-2026-1948] AGENCY: National Highway Traffic Safety Administration (NHTSA), Department of Transportation (DOT). ACTION: Interpretive rule. SUMMARY: The National Highway Traffic Safety Administration is issuing this interpretive rule regarding the scope of its authority to set fuel economy standards for commercial medium- and heavy-duty on-highway vehicles and work trucks. This rule describes NHTSA's authority to set vehicle standards, which does not include the authority to set separate standards for engines. NHTSA will review its existing standards applicable to commercial medium- and heavy-duty on-highway vehicles and work trucks for consistency with this interpretation in a separate rulemaking. Pending the rulemaking process, NHTSA will exercise its enforcement authority with regard to affected standards in accordance with the interpretation set forth in this rule. DATES: This interpretive rule is applicable as of August 31, 2026. FOR FURTHER INFORMATION CONTACT: Kerry Kolodziej, NHTSA Office of the Chief Counsel, National Highway Traffic Safety Administration, 1200 New Jersey Avenue SE, W44-308, Washington, DC 20590; email: Kerry.Kolodziej@dot.gov . SUPPLEMENTARY INFORMATION: The National Highway Traffic Safety Administration (NHTSA) issues this interpretive rule as part of its comprehensive effort to reset its fuel economy program to comply with the…
Citation: 91 FR 55788
