Lompoc, CA Noise Ordinances: Vehicle Noise (2026)

On public roads in unincorporated Santa Barbara County, vehicle noise is controlled primarily by California state law rather than a county ordinance, because the Vehicle Code generally preempts local regulation of how motor vehicles are operated and equipped. California Vehicle Code Section 27007 provides that no driver shall operate, or permit the operation of, any 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 (emergency and certain utility vehicles are exempt; parade and advertising vehicles may be further restricted by local authorities). For exhaust noise, Vehicle Code Section 27150 requires every motor vehicle to have an adequate muffler in good working order to prevent excessive or unusual noise, and Section 27151 prohibits modifying an exhaust system to amplify or increase noise, with aftermarket exhaust generally limited to 95 decibels under the applicable test standard. The County's own Chapter 40 noise ordinance targets amplified noise broadcast from buildings at night, not roadway vehicle operation. The California Highway Patrol and the Sheriff's Office enforce vehicle-noise laws on county roads. These are state standards applicable in the unincorporated area.