Whenever any ordinance designates and describes a through street, there shall be a stop sign on each and every street intersecting the through street or intersection portion thereof described and designated as such by any ordinance unless traffic at any intersection is controlled at all times by traffic control signals provided, however, that at the intersection of two through streets or at the intersection of a through street and a heavy traffic street not so designated, stop signs shall be erected at the approaches of either of the streets.
(OC, § 7-1-72)