49 CFR § 393.81 - Horn.

---
identifier: "/us/cfr/t49/s393.81"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "49 CFR § 393.81 - Horn."
title_number: 49
title_name: "Transportation"
section_number: "393.81"
section_name: "Horn."
chapter_name: "FEDERAL MOTOR CARRIER SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION"
subchapter_number: "B"
subchapter_name: "FEDERAL MOTOR CARRIER SAFETY REGULATIONS"
part_number: "393"
part_name: "PARTS AND ACCESSORIES NECESSARY FOR SAFE OPERATION"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
authority: "49 U.S.C. 31136, 31151, 31502; sec. 1041(b), Pub. L. 102-240, 105 Stat. 1914, 1993; secs. 5301 and 5524, Pub. L. 114-94, 129 Stat. 1312, 1543, 1560; and 49 CFR 1.87."
regulatory_source: "33 FR 19735, Dec. 25, 1968, unless otherwise noted."
cfr_part: "393"
---


# 393.81 Horn.

Every bus, truck, truck-tractor, and every driven motor vehicle in driveaway-towaway operations shall be equipped with a horn and actuating elements which shall be in such condition as to give an adequate and reliable warning signal.