Del Norte County, CA Noise Ordinances: Vehicle Noise (2026)

Most vehicle noise in the unincorporated area of Del Norte County is regulated by the California Vehicle Code, which preempts purely local rules for vehicles operated on public highways. Vehicle Code section 27150 requires that every motor vehicle 'be equipped with an adequate muffler in constant operation and properly maintained to prevent any excessive or unusual noise,' and prohibits cutouts or bypass devices. Section 27151 makes it unlawful to modify an exhaust system to amplify or increase noise beyond the legal limits. Vehicle Code section 27007 prohibits operating a vehicle sound amplification system that 'can be heard outside the vehicle from 50 or more feet' while on a highway, except to request assistance or warn of a hazard, with exceptions for emergency and certain utility vehicles. The California Highway Patrol and Sheriff enforce these on the road. For vehicle-related noise on private residential property (for example, an idling or revving vehicle in a yard), the county's residential noise standards and Chapter 7.08 nuisance ordinance can also apply within the unincorporated area. Crescent City may add its own enforcement within city limits.