(1) An ordinance regulating a recreational trailway is not effective unless it is posted and maintained near each gate or principal entrance to the trailway.
(2) The operation of a vehicle on a recreational trailway at a time, in a place, or in a manner prohibited by an ordinance is a municipal civil infraction, whether or not so designated by the ordinance. A civil fine ordered for a municipal civil infraction described in this subsection shall not exceed the maximum amount of a fine provided by the ordinance or $500.00, whichever is less. An act or omission described in this subsection is not a municipal civil infraction if that act or omission constitutes a violation or crime that section 21 prohibits an ordinance from designating as a municipal civil infraction.