61-8-112. Special service roads not subject to state law enforcement -- when. When forest development roads, or segments thereof, are designated as special service roads by the United States forest service and by such designation are subjected to traffic rules in addition to or in conflict with the Montana traffic laws, neither the additional nor conflicting traffic rules so prescribed by the forest service nor the Montana traffic law with which they conflict shall be within the jurisdiction of law enforcement officers of this state as to such special service road.