Alpine County, CA Noise Ordinances: Vehicle Noise (2026)

Alpine County Code Section 18.68.090 addresses recreational and property-related vehicle noise through its exemptions. 'Usual and customary activities associated with the use and maintenance of residential property' that occur between 7 a.m. and 9 p.m. are exempt from the decibel limits, and the code expressly lists personal vehicle repair and 'the lawful use of an ATV, snowmobile, motor bike, or other motorized recreational equipment' among those exempt daytime activities. Used outside that window, the same vehicles must keep sound at the parcel line within the zone limit (60–75 dB(A) Leq(15)). For on-road vehicles, mufflers and exhaust, California regulates noise statewide through the Vehicle Code — for example, Vehicle Code Section 27150 requires every motor vehicle to have an adequate muffler in good working order and prohibits cut-outs, bypasses or amplifying exhaust modifications, and Section 27151 bars modifying an exhaust system to exceed legal noise limits. Those state rules are enforced on public roads by the California Highway Patrol and the Alpine County Sheriff, and the County's noise ordinance does not set a separate roadway decibel figure. The County standard does, however, regulate noise-sensitive development setbacks from high-speed roadways (within 100 feet of a 45 mph lane, or 200 feet above 45 mph). The County standard remains designed to supplement Penal Code 370 and 415 for off-road or property-based vehicle noise.