The certified map shall show the location of existing highways and highways on plats of subdivisions that have been approved by the planning commission. Impl. am. Acts 1959, ch. 9, § 3; Acts 1965, ch. 251, § 4; impl. am. Acts 1972, ch. 829, § 7; T.C.A., §§ 54-2204, 54-19-104; Acts 1981, ch. 264, § 12.