The terms as used in this subpart are defined as follows:

(a) Commercial and industrial zones are those districts established by the zoning authorities as being most appropriate for commerce, industry, or trade, regardless of how labeled. They are commonly categorized as commercial, industrial, business, manufacturing, highway service or highway business (when these latter are intended for highway-oriented business), retail, trade, warehouse, and similar classifications.

(b) Erect means to construct, build, raise, assemble, place, affix, attach, create, paint, draw, or in any other way bring into being or establish.

(c) Federal-aid Primary Highway means any highway on the system designated pursuant to 23 U.S.C. 103(b).

(d) Interstate Highway means any highway on the system defined in and designated, pursuant to 23 U.S.C. 103(e).

(e) Illegal sign means one which was erected or maintained in violation of State law or local law or ordinance.

(f) Lease means an agreement, license, permit, or easement, oral or in writing, by which possession or use of land or interests therein is given for a specified purpose, and which is a valid contract under the laws of a State.

(g) Maintain means to allow to exist.

(h) Main-traveled way means the traveled way of a highway on which through traffic is carried. In the case of a divided highway, the traveled way of each of the separate roadways for traffic in opposite directions is a main-traveled way. It does not include such facilities as frontage roads, turning roadways, or parking areas.

(i) Sign, display or device, hereinafter referred to as “sign,” means an outdoor advertising sign, light, display, device, figure, painting, drawing, message, placard, poster, billboard, or other thing which is designed, intended, or used to advertise or inform, any part of the advertising or informative contents of which is visible from any place on the main-traveled way of the Interstate or Primary Systems, whether the same be permanent or portable installation.

(j) State law means a State constitutional provision or statute, or an ordinance, rule or regulation, enacted or adopted by a State.

(k) Unzoned area means an area where there is no zoning in effect. It does not include areas which have a rural zoning classification or land uses established by zoning variances or special exceptions.

(l) Unzoned commercial or industrial areas are unzoned areas actually used for commercial or industrial purposes as defined in the agreements made between the Secretary, U.S. Department of Transportation (Secretary), and each State pursuant to 23 U.S.C. 131(d).

(m) Urban area is as defined in 23 U.S.C. 101(a).

(n) Visible means capable of being seen, wehter or not readable, without visual aid by a person of normal visual acuity.