Every campground hereafter established shall be laid out with, and all existing campgrounds shall provide, unoccupied space of not less than 600 square feet for each trailer, not including space directly under any portion of any camp car or trailer. Camp cars and trailers shall be arranged in rows abutting or facing on a driveway or clear unoccupied space of not less than 18 feet in width, which space shall have unobstructed access to a public street or alley.
(`78 Code, § 5.48.140.)