After any plan for major highways, or portion thereof, has been prepared by the county planning commission, filed and certified as provided in section 64.550, the county commission shall be authorized and empowered to establish, regulate and limit building or setback lines on such major highways outside the corporate limits of municipalities and to prohibit any new building being located within such building or setback lines, and to amend such regulations from time to time. All orders of the county commission relating to such building or setback lines shall be entered of record and certified copies thereof shall be filed with the county planning commission, and in the office of the recorder of deeds.