For purposes of sections 39-202 to 39-226:

(1) Highway Beautification Control System means the National System of Interstate and Defense Highways, the system of federal-aid primary roads as they existed on June 1, 1991, any additional highway or road which is designated as a part of the National Highway System under the federal Intermodal Surface Transportation Efficiency Act, and scenic byways. A map of the Highway Beautification Control System shall be maintained as provided in section 39-1311;

(2) Scenic byway means a road, highway, or connecting link designated as a scenic byway pursuant to section 39-217. A map of the scenic byways shall be maintained as provided in section 39-1311; and

(3) Visible, in reference to advertising signs, displays, or devices, means the message or advertising content of such sign, display, or device is capable of being seen without visual aid by a person of normal visual acuity. A sign is considered visible even though the message or advertising content can be seen but not read.