When a tract fronting on a major road for a distance of 500 feet or more and an average depth from the major road of more than 350 feet is to be subdivided into more than eight residential lots, the commission may require such residential lots adjoining the major road to be provided with frontage on a secondary or interior street. (Ord. 152 § 1, 1971; 1978 code § 15.108.3)