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

Glenn County's 2023 noise ordinance reaches vehicle-borne amplified sound. Section 10.25.020(A)(2) of the Glenn County Code makes it unlawful to use or operate audio equipment 'from any motor vehicle on any county roadway with volume louder than is necessary for convenient hearing for the persons who are in the motor vehicle.' The objective standard is stricter for vehicles than for buildings: operation 'in such a manner as to be plainly audible at any time at a distance of ten (10) feet from the motor vehicle in which it is located shall be prima facie evidence of a violation.' Unlike the residential 50-foot rule, this 10-foot vehicle test applies 'at any time,' not only during night hours. Engine, exhaust, and muffler noise are not in the county ordinance; those are controlled by California state law, principally Vehicle Code sections 27150 and 27151, which require an adequate muffler and prohibit modified exhaust systems that amplify noise, and Vehicle Code section 23130-era sound standards. The California Highway Patrol and the Glenn County Sheriff enforce the Vehicle Code on county roads. These county provisions apply in unincorporated Glenn County; Willows and Orland have separate municipal rules.