16.70.520 Hitching Onto Vehicle.
A. It is unlawful for any person riding upon any vehicle, sled, or other conveyance to hitch or hold on to any part of another vehicle or conveyance for the purpose of being propelled or drawn along any street or highway within the City.
B. Nothing contained in this Section is deemed to prohibit the coupling of one or more motor vehicles or motor vehicle and trailer in the manner approved by ORS 818.
Article III – Parking, Standing, or Stopping Sec. 15 Parking Prohibited: No person shall park a vehicle at any time upon any of the streets or parts of streets described: Main St. (West) In front of Dunkin Donuts to a point 25 feet south. Main St. (East) From the southern entrance of the Municipal office….
198-14. Disrobing in public. No person shall disrobe under the boardwalk, on the beach or in any vehicle or truck while such vehicle is parked upon any public street or way or other public place in plain view of the public.
There are lots of references to this law, but it may be directed toward the drivers or passengers of motorcycles.