In all actuality the jake brake, compression brake, engine retarder, or what ever the manuf. calls it is a BRAKE on a COMMERCIAL vehicle which is under FEDERAL regulation! I have beat a muni ticket for Jake use where prohibited! Since it is a brake, and up to the drivers digression as to when it is needed, no government agency can lawfully decide when you use any braking device. I ask the judge if he really wants to have his Court looked at by the Federal DOT, too see if your ordnance is legal?
Just like setting the parking brake. That air shot can be heard for blocks! But a cop can't ticket you for setting your parking brake if you are parking waiting for a place to open! If you need that extra braking help from the Jake, their ticket is illegal! And a noise ordnance is just that "Unnecessary noise of excessive exhaust, loud music, yelling in a fight, barking dogs, NOT Jake brakes!
All it will take is for one driver to testify the :if I could have used my jake brake, I wouldn't have had the accident, and I wouldn't be suing the municipality