Grand Junction, CO Noise Ordinances: Vehicle Noise (2026)

GJMC § 10.04.225 requires every motor vehicle subject to registration and operated on a highway in the City of Grand Junction to run an adequate muffler, in constant operation and properly maintained, that prevents excessive or unusual noise; the section bars any cut-off, bypass, or similar device on the exhaust, and bans modifying the system to amplify noise beyond what the factory-installed muffler produced. Subsection (1.5) goes further for commercial vehicles equipped with an engine compression brake, as defined at GJMC § 10.04.235(1)(a): those trucks are required to carry a muffler, and a violation carries a stated $500.00 fine on conviction rather than the standard traffic-infraction treatment.

A plain muffler violation under subsection (1) is a traffic infraction, and subsection (4) exempts electric motor vehicles from the whole section entirely. The Code pairs the muffler rule with a separate engine-retarding-brake ban at GJMC § 10.04.223(3): it is unlawful to use a compression brake, exhaust brake, or similar mechanical device on any City street unless doing so is necessary to avoid immediate physical harm to persons or property. The City Manager posts "ENGINE RETARDING BRAKE ORDINANCE ENFORCED" signs at the locations where the ban applies, and no such sign can go up on a State highway without Colorado Department of Transportation sign-off; emergency vehicles are exempt from the prohibition.

Grand Junction Police Department officers enforce both rules on patrol and at accident scenes; unless a section states its own fine, GJMC § 10.04.1701 caps a general traffic infraction penalty at $1,000, alongside possible community service or driver-education requirements, with fines paid through the Municipal Court Violations Bureau.