To ensure the functional enhancement of major streets and safety of the traveling public as pertains to adequate visibility, no building permit shall be issued for any building or structure to be located within the designated building setback of a major street as established and shown on the adopted General Plan. Except as otherwise provided, building setback lines shall be measured from the centerline of major streets. Centerlines shall be determined by the City Engineer.
(`78 Code, § 17.86.010.)