Weld County, CO Noise Ordinances: Vehicle Noise (2026)

D sets two vehicle classes. Any motor vehicle or combination with a gross vehicle weight rating under 10,000 pounds, including cars, motorcycles, vans and light trucks, is capped at 80 dB(A) in a posted speed zone of 35 mph or less and 84 dB(A) where the speed limit runs higher. Heavier rigs, those with a manufacturer's gross vehicle weight rating over 10,000 pounds or any combination towed by one, are allowed up to 86 dB(A) in the slower zone and 90 dB(A) in the faster one.

Subsection E separately requires every vehicle operated anywhere in the county to run 'a muffler in constant operation which is properly maintained to prevent noise in excess of that set forth in this Section,' and bars operating in unincorporated Weld County with a muffler 'equipped or modified with a cutoff, bypass or similar device or modification,' meaning aftermarket cutouts and muffler deletes are illegal regardless of the actual decibel reading. 5 sets the measurement method deputies use: a sound meter placed at least 25 feet from the mid-point of the traffic lane being monitored, at a height of at least 4 feet, with valid readings only in wind of 5 mph or less, or 25 mph with a windscreen on the microphone.

B separately bars operating any motor vehicle or motorcycle off a public right-of-way in a way that exceeds the same § 14-9-40 limits, covering off-road use on private land within earshot of neighbors. Agricultural equipment used on a farm or ranch is exempt from the whole Article, including from these vehicle limits.