Flagstaff, AZ Noise Ordinances: Vehicle Noise (2026)

Flagstaff City Code § 9-01-001-0010, subsection A, makes it unlawful for anyone to intentionally operate a vehicle at a speed on a curve or turn, or to accelerate or decelerate it, in a manner that produces loud and unnecessary noise through squealing tires or that damages the roadway; this rule targets the classic tire-screech complaint rather than mechanical vehicle sound. Subsection B separately bars engine compression braking, defined as the action a diesel truck or bus operator takes to slow the vehicle by activating a device that engages the engine's own compression braking, on any City street outside of an emergency; this is the section that reaches the loud engine-brake noise heard from trucks descending grades on routes like I-40 and I-17 through Flagstaff.

A vehicle's stereo or other sound amplification system is regulated separately, under Flagstaff City Code § 6-08-001-0006, and the fixed decibel ceilings for a vehicle's engine and exhaust noise sit in the adjoining § 6-08-001-0004, so a single loud vehicle can be cited under more than one section depending on the source of the noise. Neither subsection of § 9-01-001-0010 prints its own dollar fine, so Flagstaff's general penalty clause, City Code § 1-04-001-0001, applies by default: a conviction is a misdemeanor punishable by a fine of up to $2,500 and up to 90 days in the Coconino County jail, with each day a violation continues treated as a separate offense. The Flagstaff Police Department enforces both subsections as traffic offenses.