Alhambra, CA Noise Ordinances: Vehicle Noise (2026)

The City of Alhambra does not set its own decibel limit for moving traffic; its noise ordinance defers to state law. Section 18.02.060(E) of the Municipal Code exempts from the city's noise standards any activity whose regulation has been preempted by state or federal law, and it specifically names motor-vehicle, aircraft-in-flight, and railroad noise as preempted categories. For on-road vehicles, the controlling rules are in the California Vehicle Code. Section 27150 requires every motor vehicle to be equipped at all times with an adequate muffler in constant operation, properly maintained to prevent excessive or unusual noise, and prohibits cutouts or bypass devices. Section 27151 makes it unlawful to modify an exhaust system in a way that amplifies or increases noise beyond the limits, or to operate a vehicle with such a modified system; for passenger vehicles under 6,000 pounds gross weight (other than motorcycles), a sound level of 95 dBA or less complies. These are enforced by police as Vehicle Code violations, not under Chapter 18.02. Where a vehicle is parked and its accessories (such as a sound system or refrigeration unit) generate stationary noise on private property, the general Section 18.02.050 dBA standards can still apply, but engine/exhaust noise from vehicles in operation is a state matter. As an incorporated city, Alhambra relies on these state standards rather than Los Angeles County's code.