Janesville, WI Noise Ordinances: Vehicle Noise (2026)

Section 38-254(a) makes it unlawful to make unnecessary and annoying noise with a motor vehicle by squealing tires, excessively accelerating the engine, emitting unnecessary and loud muffler noise, or running a modified or inadequately maintained exhaust or braking system. Subsection (b) exempts noise from an emergency maneuver, defined in Subsection (c) as circumstances an alert driver could not reasonably foresee, such as swerving or braking hard to avoid hitting a pedestrian, animal, fixed object or another vehicle; emergency vehicles are also exempt. A second, separate article addresses engine braking specifically: Section 38-280 finds that dynamic braking devices, commonly known by the trademarks "Jake Brakes" or "Jacobs Brakes," disturb the public peace and quiet, and Section 38-282 makes it unlawful to cause unreasonable, loud or excessive noise anywhere in the City by operating a vehicle with a dynamic braking device engaged, except to avoid imminent danger to persons or property.

Section 38-284 requires the Director of Public Works to post signs on the main arterial highways and truck routes entering the City stating that the engine-brake ban is in effect, coordinated with State approval. Emergency vehicles are exempt from the dynamic-braking article under Section 38-283. Enforcement of both articles falls to the Janesville Police Department, and each carries its own violation section rather than a single shared penalty.