49 CFR § 523.6 - Heavy-duty vehicle.
---
identifier: "/us/cfr/t49/s523.6"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "49 CFR § 523.6 - Heavy-duty vehicle."
title_number: 49
title_name: "Transportation"
section_number: "523.6"
section_name: "Heavy-duty vehicle."
chapter_name: "NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION"
part_number: "523"
part_name: "VEHICLE CLASSIFICATION"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
authority: "49 U.S.C. 32901; delegation of authority at 49 CFR 1.95."
cfr_part: "523"
---
# 523.6 Heavy-duty vehicle.
(a) A heavy-duty vehicle is any commercial medium- or heavy-duty on-highway vehicle or a work truck, as defined in 49 U.S.C. 32901(a)(7) and (19). For the purpose of this section, heavy-duty vehicles are divided into four regulatory categories as follows:
(1) Heavy-duty pickup trucks and vans;
(2) Heavy-duty vocational vehicles;
(3) Truck tractors with a GVWR above 26,000 pounds; and
(4) Heavy-duty trailers.
(b) The heavy-duty vehicle classification does not include vehicles excluded as specified in 49 CFR 535.3.
[81 FR 74237, Oct. 25, 2016, as amended at 89 FR 52945, June 24, 2024]