(A)   Wherever the location of a street is indicated in the Thoroughfare Plan as following an existing road or street, or a section or half-section or other established property line, the location of the street shall conform to that location; however, a street lying wholly within a subdivision, and not designated as following an existing road or established property line, may be varied in its alignment when the variance promotes the plan of a neighborhood development unit in accordance with good site planning principles, and if an alignment provides for the continuity of traffic movement.
   (B)   Wherever the location of a street is indicated in the thoroughfare plan as following an irregular alignment, or a revised alignment, or is not referenced to an established line, it shall follow the alignment shown in the Plan. The alignment shall be subject to a detailed survey which may be made by the Area County Plan Commission or other public agencies, of by the owners of land to be subdivided if required by the Commission. The survey for the street shall be subject to the approval of the commission prior to the dedication of the street.
('71 Code, § 130.06)