San Leandro, CA Noise Ordinances: Vehicle Noise (2026)

On public roadways, vehicle noise is governed by California Vehicle Code §27150 (every motor vehicle must be equipped with an adequate muffler in constant operation to prevent excessive or unusual noise; no cutout, bypass, or similar device), §27151 (no modification of exhaust to amplify or increase noise above factory level), and the corresponding A-weighted decibel schedules in §27201 et seq. AB 1824 (effective Jan. 1, 2019) eliminated the prior 'correctable' citation status — officers may now issue immediate fines up to $1,000 for excessive exhaust under §27151. Vehicle horns must be audible from 200 feet but cannot emit an 'unreasonably loud or harsh sound' (§27000). Locally, SLMC §4-1-1115 (Prohibited Acts) restricts the 'sustained operation or use between the hours of 9:00 p.m. and 8:00 a.m. of any electric or gasoline powered motor or engine or the repair, modification, reconstruction, testing or operation of any automobile, motorcycle, sweeper, vacuum, public address system, whistle muffler, motorized scooter, machine or mechanical device' unless enclosed within a sound-insulated structure so noise is not plainly audible from any residential property line. Vehicle-mounted amplification on highways is independently regulated by CVC §27007 (50-foot audibility rule).