23 CFR §752.9

1. (a)Acquisition of interests in and improvement of strips of land or water areas adjacent to Federal-aid highways may be made as necessary for restoration, preservation, and enhancement of scenic beauty.
2. (b)Scenic strip interests may be acquired in urban or rural areas, combined in one or more projects, authorized separately whether or not there is or has been a Federal-aid project on the adjoining Federal-aid highway.
3. (c)Approval of acquisition and development of scenic strips on completed Interstate should be conditioned on a showing that the acquisition of scenic strips was considered under the Highway Beautification Program for that particular section of Interstate.