The Council may determine those portions of any street where overtaking and passing a vehicle proceeding in the same direction or driving to the left of the roadway would be especially hazardous and may by appropriate signs or markings on the roadway, indicate the beginning and end of such zones. When such signs or markings are in place and clearly visible to an ordinarily observant person, every driver of a vehicle shall obey the directions thereof.
('86 Code, § 18.216) Penalty, see § 70.99