Obstructions. No person may place, maintain, or allow any obstructions in the clearance zone other than those specifically permitted by this overlay district, by state law or rule, or by written approval of the Town Board. Items prohibited by this section include, but are not limited to, fences, posts, structures, piled materials, hay bales, vehicles, trailers, campers, equipment, or any other items that interfere with the safe use or the maintenance of the clearance zone. No person shall park a functioning vehicle in the clearance zone in such a way as to unreasonably interfere with safe use of the road or the maintenance of the clearance zone.