St. Louis County, MO Noise from Specific Sources: Delivery Truck Noise (2026)

010 is the county's core vehicle-noise rule, and it reaches truck traffic in two distinct ways. First, it flatly bans 'muffler cutouts' on any vehicle and requires every motor to be 'fitted with properly attached mufflers of such capacity or construction as to quiet the maximum possible exhaust noise,' with any cutout in the exhaust pipe required to be 'completely closed and disconnected from its operating lever' so it cannot be opened while the vehicle is moving. That covers a delivery truck running an unmuffled or cut-out exhaust through a residential subdivision.

Second, and separately, subsection 2 makes it unlawful to 'drive a vehicle in a manner or condition such that excessive and unnecessary noises are made by its machinery, motor, signaling device, tires, or other parts, or by any improperly loaded cargo,' language that squarely covers a delivery truck's rattling lift gate, an unsecured load banging in the bed, or engine noise beyond what the vehicle's equipment should produce. 010 doesn't require a distance test at all: it is a vehicle-equipment and vehicle-operation standard enforced by St. Louis County Police on the road, independent of the county's separate loud-noise disturbance rule. 010.