(1) After the preparation of a master plan or at least a major street plan, the planning commission may make studies or surveys of new, extended, widened, or narrowed highways, or of the vacation or abandonment of highways, and may make and certify to the legislative body a map of the area studied or surveyed that shall show the recommended future highways, extensions, widenings, narrowings, or abandonments, including any state and federal highway or abandonment proposed by the commissioner.
(2) The certified map shall show the location of existing highways and highways on plats of subdivisions that have been approved by the planning commission.