Motor vehicles which are stalled or disabled so that they are unable to move by their own power and non-self propelled vehicles which are disabled so that they cannot be towed by the animal or motor vehicle with which they are normally combined, may be removed by the authority and parked elsewhere on authority property, or parked, garaged, or stored elsewhere at the risk and expense of the owner. Vehicles left unattended may be parked, garaged, or stored at the risk and expense of the owner, except that vehicles may be parked in such places as may be designated by the authority as parking areas for periods not in excess of 48 hours.