Section 13B. The department may acquire by eminent domain under the provisions of chapter seventy-nine or by purchase or otherwise land and rights in land within or adjacent to federal-aid highways of the commonwealth for the purpose of restoring, preserving and enhancing scenic beauty, or, with the approval of the Massachusetts historical commission and subject to the availability of federal reimbursement, historic or archeological sites, and of providing publicly owned and controlled rest and recreation areas and sanitary and other facilities to accommodate the traveling public. The department may improve such lands, and may expend for the purposes of this section such sums as may be appropriated therefor.