haulrecordFMCSA data

Violation codes / 393.81-H

49 CFR 393 · Parts and accessories

393.81-H

What it means

Horn - Inoperative or defective

What the rule actually says

This violation cites 49 CFR 393.81, horn. The regulation reads:

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.

49 CFR 393.81, Horn. Read the full section on eCFR

Quoted verbatim from the Electronic Code of Federal Regulations. Nothing here is a paraphrase, and nothing here is legal advice on a citation.

Times recorded15,3463% as often as 393.9, the most cited
How common184thof the 200 most cited codes, out of 2,372 that exist
Regulation393.81Parts and accessories

How often this comes up

This violation was recorded 15,346 times across the roadside inspections in the FMCSA file, making it the 184th most frequently cited code. Whether a given instance puts a vehicle or driver out of service is decided at the roadside by the inspector, not by the code itself, so the same violation can end a trip or simply be noted.

It sits under 49 CFR Part 393, which covers parts and accessories. To see it in context, look up a carrier and read its inspection history: the same code appearing repeatedly is a different signal from a single occurrence.

Look up a carrier's inspection record

Other parts and accessories violations

Counts are from the FMCSA Inspections and Violations file via data.transportation.gov. This describes how the violation is recorded, and is not legal advice on a citation.