A.   Where uncertainty exists with respect to the boundaries of various zones, the following rules shall apply:

      1.   Street or Alley Lines. Where the intended boundaries on the zone map are approximately street or alley lines, said street or alleys shall be construed to be the zone boundaries;

      2.   Lot Lines. Where the indicated boundaries are approximately lot lines, said lot lines shall be construed to be the zone boundaries, unless otherwise indicated;

      3.   Unsubdivided Land. Where land has not been subdivided into lots, the zone boundary shall be determined by the use of the scale of measurement shown on the map; and

      4.   Uncertainty. Where other uncertainties exist, the Planning Commission shall interpret the map.