No person shall ride or drive upon any part of or portion of any park at a rate of speed exceeding eight (8) miles per hour, nor upon any parkway at a rate of speed exceeding fifteen (15) miles per hour, except upon such portion thereof as the Director of Public Properties may designate for greater speeds. Every person using the driveways, roads, parkways and bridle paths shall, as to the rate of speed of driving or riding thereon, and as to moving or driving on, or stopping any vehicle, horse or team in such rides or drives, be subject to and obey the orders of any park officer.