Upon those streets and parts of streets and in those alleys designated by order, rule or regulation of the legislative authority of the City, subject to the approval of the State Highway Commission in cases involving state highways, vehicular traffic shall move only in the indicated direction when signs indicating the direction of traffic are erected and maintained at every intersection where movement in the opposite direction is prohibited. A vehicle passing around a rotary traffic island shall be driven only to the right of such island. (Ord. 304 § 45, 1963).