Council Bluffs, IA Noise Ordinances: Vehicle Noise (2026)

Council Bluffs Municipal Code § 4.50.090 sets Table 2 sound limits for a moving motor vehicle or motorcycle on a public right-of-way, measured at fifteen meters (fifty feet): an ordinary passenger vehicle may not exceed 76 dBA in a 35 mph-or-less zone, 82 dBA over 35 mph, or 85 dBA on a stationary run-up, with higher ceilings for heavy trucks and motorcycles. Separately, the "Adequate Mufflers or Sound Dissipative Devices" clause makes it unlawful to operate any vehicle on a public right-of-way without a muffler or sound dissipative device in good working order and constant operation that reduces sound to an acceptable level, and bars removing or rendering a muffler inoperative except for maintenance, repair or replacement.

Chapter 9.72.320, in the traffic title, separately forbids any cutout, fitting or device that lets exhaust gas escape without passing through a silencer or expansion chamber, and bars driving with the exhaust system, including the muffler, out of proper working condition or with the muffler's cutout open. Between the two chapters, an unmuffled car, a modified stereo audible beyond the driver, and an aftermarket exhaust bypass are all independently regulated. The chief building official and Council Bluffs Police Department enforce chapter 4.50 under § 4.50.040, and § 9.72.320 sits within the traffic code enforced through the same citation process.