(1) Off-premise mobile advertising devices on vehicles which are traveling on controlled routes are not subject to the provisions of the Outdoor Advertising Act or administrative rules while traveling.

(2) Vehicles, trailers, or other portable objects displaying off-premise mobile advertising devices being used for outdoor advertising purposes must not be parked on public or private land visible to the traveling public from any place on a controlled route, whether the display is permanent or portable, regardless of the length of time the vehicle is parked in any one or more locations.

(3) Signs on registered or unregistered motor vehicles, including but not limited to: semi-truck trailers, buses, trucks, RVs, mobile homes, or similar wheeled conveyances, which are determined by the department to be permanently or semi-permanently parked and clearly advertising to a controlled route shall be prohibited unless properly permitted under the provisions of the Outdoor Advertising Act and these administrative rules.