No driver of a vehicle shall either make a left turn across any traffic lane which permits vehicles to travel in an opposite direction to him or make a U-turn, when upon any curve, grade, or behind any obstruction, whether such obstruction is moving or not, where such vehicle cannot be seen by the driver of any other vehicle approaching from either direction within 300 feet.
('74 Code, § 9-5-8.8) (Ord. 65-1974)