Portland, ME Noise Ordinances: Vehicle Noise (2026)

Sec. 17-20 (Creation of Certain Noise Upon Public Right of Way) is Portland's primary vehicle-noise rule. Section 17-20(c) flatly prohibits any person on a public right-of-way from operating a 'noise-creating device' in a manner that 'the public's attention is drawn to the source of the noise.' The ordinance enumerates specifically prohibited conduct: (a) discharging fireworks; (b) firing a starter pistol, air gun, BB gun, or firearm; (c) sounding a bell or whistle for an extended time; (d) 'Rapid throttle advance and/or revving of an internal combustion engine resulting in increased noise from the engine'; and (e) 'Operation of motor vehicle... including but not limited to a motorcycle with a straight pipe exhaust system, an exhaust system with a cutout, bypass or similar device or an exhaust system that does not meet the requirements of Maine law, including, but not limited to, 29-A M.R.S.A. § 1912.' 'Straight pipe exhaust system' is defined in § 17-20(b)(6) as any straight-through muffler without baffles, including glass packs, steel packs, and straight pipes. State law (29-A MRS § 1912) independently requires that every motor vehicle be equipped with a muffler in good working order that prevents excessive or unusual noise. Sec. 17-20(d) exempts First-Amendment-protected expression, state-preempted activity, government operations, permitted noises, and lawful signaling devices. Sec. 17-21 separately limits motor-vehicle audible burglar alarms to 10 aggregated minutes in any 60-minute period (20 minutes if actually triggered by a burglary attempt, with burden of proof on the owner). Owner liability applies regardless of who possesses the vehicle, except where it was stolen and reported within 24 hours.