I learned about 23 CFR 1.23(b) of the Code of Federal Regulations, which provides:
(b) Use for highway purposes. Except as provided under paragraph (c) of this section, all real property, including air space, within the right-of-way boundaries of a project shall be devoted exclusively to public highway purposes. No project shall be accepted as complete until this requirement has been satisfied. The State highway department shall be responsible for preserving such right-of-way free of all public and private installations, facilities or encroachments, except (1) those approved under paragraph (c) of this section; (2) those which the Administrator approves as constituting a part of a highway or as necessary for its operation, use or maintenance for public highway purposes and (3) informational sites established and maintained in accordance with ? 1.35 of the regulations in this part.I obtained a copy of a letter, dated January 12, 2012, from Mark D. Bartlett, P.E., Alabama Division Administrator to Mr. John R. Cooper, Director of the Alabama Department of Transportation, concerning political signs on highway right of way, saying that political signs are not an approved use under 23 CFR 1.23(b).
I was told by Mr. Don Crow, an Assistant Permit Manager in the Third Division of District 5 of the Alabama Department of Transportation, that some Ron Paul supporters standing with signs on the side of Highway 280 were told by the Alabama Department of Transportation that their activity was not permitted and they were told to remove themselves from where they were standing.