Ames, IA Noise Ordinances: Vehicle Noise (2026)

Sec. 16.5 of the Ames Municipal Code, part of Chapter 16's Noise Control provisions, targets motor vehicle noise specifically rather than relying on the general Sec. 16.4 decibel table. It is unlawful for any person to operate, or for an owner to cause or permit the operation of, a motor vehicle on the city's public right-of-way that emits noise above 75 dB(A) measured at a distance of twenty-five feet. Sec. 16.5(2) makes clear the limit covers the vehicle's total noise output and does not narrow enforcement of any other noise provision in the code, so a loud vehicle can still be cited under Sec.

16.4 as well. Sec. 16.5(3) separately bars modifying a vehicle's exhaust system or any other noise abatement device, or operating a vehicle so modified, in a way that makes it louder than it was as originally manufactured; muffler cutouts and bypass devices are named as unlawful outright. Measurements are taken on an A-weighted, slow-response sound level meter, the same standard used for the general noise table under Sec. 16.3. Because Sec. 16.5 sits inside Chapter 16, a violation is enforced under Sec. 16.9 as a municipal infraction, $50 for a first violation and $100 for each repeat, with the option for a peace officer to instead charge a simple misdemeanor. Emergency vehicles responding to a call are excused from the chapter's requirements under Sec. 16.8.