Norman, OK Noise Ordinances: Vehicle Noise (2026)
Key Facts
- Heavy trucks (10,000+ lb GVWR)
- 88 dB(A) limit
- Motorcycles/other vehicles
- 78 dB(A) limit
- Measurement point
- 25 feet from nearest lane, 5 ft height
- Exhaust requirement
- Working muffler, no cut-out or bypass
- Engine (Jacobs) brakes
- Banned except to avert imminent danger
Summary
NCC 16-206 limits motor vehicle noise measured at 25 feet: 88 dB(A) for trucks rated 10,000 pounds GVWR or more, and 78 dB(A) for motorcycles and every other vehicle, and separately requires every vehicle to run a defect-free exhaust with a working muffler and no cut-out or bypass device.
No person shall drive or move or cause or knowingly permit to be driven or moved a motor vehicle or combination of vehicles at any time in such a manner as to exceed the following noise limits for the category of motor vehicle shown below. The standard measurement height shall be five feet (1.5m) and the measurement distance no less than 25 feet (7.5m). The distance shall be measured from the near side of the nearest monitored traffic lane to the microphone. ... No person shall operate or cause to be operated any motor vehicle unless the exhaust system of such vehicle is: Free from defects which affect sound reduction; Equipped with a muffler or other noise dissipative device; and Not equipped with any cut-out, by-pass or similar device.
Full Breakdown
NCC 16-206 sets a fixed measurement protocol: a microphone height of five feet and a distance of no less than 25 feet from the near side of the nearest monitored traffic lane. Against that protocol, heavy vehicles, those with a manufacturer's gross vehicle weight or combination weight rating of 10,000 pounds or more, cannot exceed 88 dB(A); motorcycles and every other vehicle or towed combination cannot exceed 78 dB(A). The section applies to the vehicle's total noise and does not limit enforcement of other muffler-related provisions elsewhere in the code.
Separately, every vehicle operated in Norman must have an exhaust system free of defects affecting sound reduction, fitted with a muffler or other noise-dissipative device, and free of any cut-out, bypass, or similar device that would let exhaust bypass the muffler. NCC 16-208 adds a related ban on dynamic engine braking devices, commonly called Jacobs Brakes, except when used to avert imminent danger. The Norman Police Department enforces both the decibel limits and the exhaust-equipment requirements.
Violations & Fines
A vehicle exceeding NCC 16-206's decibel limits, or running a defective, unmuffled, or cut-out exhaust, is punishable under NCC 16-211 by a fine and/or imprisonment set by the City's penalty and fine schedule, with each violation charged separately, and NCC 16-212 allows the City to pursue injunctive relief for a continuing violation of the noise article.
Frequently Asked Questions
How loud can a truck legally be on Norman streets?
Is it illegal to use an engine brake in Norman?
What if my car's exhaust has a hole or a cut-out pipe?
Sources & Official References
Other rules in Norman
Compare Norman to another location·View the Oklahoma noise ordinances overview
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