One freestanding sign may be erected to identify a retail center and to list individual occupants, provided that not more than one such sign shall be erected for 300 feet of frontage on a public street, and further provided that the aggregate area of all sides of any such sign shall not exceed 50 square feet. Such signs may be illuminated, but shall not be of the flashing type, shall not exceed the height of 15 feet, shall not be located within 15 feet of a public street or parking area driveway or within 100 feet of the boundary of a residence zone and shall in no way interfere with the safe functioning of any traffic control signal, directional device or sight distance.