Why are motorcycles excempt from Wisconsin Statute 347.39 (mufflers)?

Question

I once requested the number of citations issued by the Milwaukee Police Department in a certain period for motorists failing to comply with statute 347.39. I do not remember the exact number, though I do remember it was approximately 80. Zero of those were written against motorcycles. All were written against cars or trucks. I find that odd because motorcycles are the biggest noise offenders on the road. Many Harleys have been modified and have no muffler at all--just pipes. They are so loud that the noise is painful if you are next to one starting out. I have asked the police why they do not enforce this law to motorcycles and have gotten no satisfactory answer. Does anybody know?

Answer 1

State law can not be more restrictive than federal law. These Harleys pass federal guidelines, even though they are louder than any other vehicles on the road.

As far as the ones that are modiifed, keep in mind officers are not mechanics, and it can be difficult to determine if modifications are made.