People often think there are no federal laws covering noise in the United States because the Office of Noise Abatement and Control was defunded in 1982, but there are federal regulatory codes that address specific sounds. The Uniform Vehicle Code serves as a standard for vehicle sounds, at least up to the year 2000.
U.S. state vehicle codes are guided by the Uniform Vehicle Code, which includes a section on horn use.
Most U.S. state laws mention horn use, found in this document. A similar list of state codes can be found in the appendix of the Porter v. Martinez decision related to legal and illegal horn use.
There are state and municipal laws that define legal and illegal use of vehicle horns. In this list, we only include noise ordinances that mention vehicle horn use. You will find several hundred United States noise ordinances on the Noise Pollution Clearinghouse Law Library page, with and without mention of horn use.
U.S. and Canadian noise ordinances, codes, regulations, and bylaws with mention of horn regulation are organized alphabetically by city or municipality.
With all ordinances, requiring that a horn only be used when a car is in motion seem stronger in the context of non-emergency horn-based lock signals, but the limitations of legal horn use are clearly spelled out in the Uniform Vehicle Code and the state codes listed.
The list of local laws below is a work in progress, and contributed links can be sent by email.
Why does this matter?
Automakers avoid responsibility and liability for consumer use of horn sounds that indicate lock status and remote start status (and other nonemergency horn honking) by stating in owner manuals that one should become familiar with local noise codes and ordinances related to horn honking for convenience (to ensure that the car is locked, or to let you know the car started remotely) if you "choose" to use the horn for one of these reasons. But this is misleading. It's always helpful to become familiar with local noise codes and ordinances, but for regulation of vehicle horns, most state regulation does not allow nonemergency horn use, and the Uniform Vehicle Code plainly states the limitations of vehicle horn use, in any location.
“The driver of a motor vehicle shall when reasonably necessary to [ensure] safe operation give audible warning with the horn but shall not otherwise use it.” Uniform Vehicle Code § 12-401(a) (National Committee on Uniforn Traffic Laws and Ordinances 2000)
Automakers also avoid responsibility and liability for consumer use of horn sounds to give them "assurance" that their car doors are locked by stating that actuating the horn sound is a "choice" because it only takes one press of a key fob to lock the car. The "choice" to create a horn sound by pressing the key fob button a second time is up to the consumer.
Local Codes and Ordinances, United States
Alabama
Birmingham (page 3 section 11-8-23)
Alaska
Anchorage Noise Related Regulations (page 11)
Arizona
Avondale noise ordinance (page 1)
Arkansas
California
Colorado
Arvada (page 6, Section 38-62, 4a, 4b for exceptions)
Boulder noise regulation (2, 3, 4, 5, and 7)
Denver noise ordinance (page 7)
Connecticut
Bridgeport noise control regulation (page 5 mention of noise "while not in motion")
Delaware
District of Columbia
District of Columbia (2, 5)
Florida
Miami Lakes Code of Ordinances
Miami-Dade County Noise Ordinance
Illinois
Chicago
Chicago
Maryland
Baltimore
Michigan
Dearborn Code of Ordinances (page 2)
New Jersey
Noise Control Code for all Municipalities in Hudson County (page 10)
Chatham Township, Morris County (page 2)
New York
Town of Cortlandt Unnecessary Noise
About the New York City Noise Code
City of New York Local Law No. 113
City of Yonkers enumeration of prohibited noises (Section 66-4 E)
Local Codes and Ordinances, Canada
Toronto
Toronto municipal noise code (page 6)
City of Windsor
City of Windsor By-law 6716 (pages 3 and 4)
