Signs permitted in protected areas on the interstate and federal-aid primary limited and non-limited access highways

and non-limited access highways Erection and maintenance of the following signs may be permitted in protected areas: (1) Official signs: Directional or other official signs or notices erected and maintained by public officers or agencies pursuant to and in accordance with direction or authorization contained in state or federal law, for the purpose of carrying out an official duty or responsibility. (2) On premises signs: Signs not prohibited by state or local law which are consistent with the applicable provisions of this section and sections 13a-123-4 and 13a-123-13 and which advertise the sale or lease of, or activities being conducted upon, the real property where the signs are located. Not more than one such sign advertising the sale or lease of the same property may be permitted under this section in such a manner as to be visible to traffic proceeding in any one direction on any interstate or federal-aid primary highway. Not more than one such sign, visible to traffic proceeding in any one direction on any one interstate or federal-aid primary highway, and advertising activities being conducted upon the real property where the sign is located, may be permitted under this section more than fifty feet from the advertised activity. Signs permitted under this section may display trade names.