The following terms when used in the standards in this part have the following meanings:

(a) Acquired for right-of-way means acquired for right-of-way for any public road by the Federal Government, a State, or a county, city, or other political subdivision of a State, by donation, dedication, purchase, condemnation, use, or otherwise. The date of acquisition shall be the date upon which title (whether fee title or a lesser interest) vested in the public for right-of-way purposes under applicable Federal or State law.

(b) Centerline of the highway means a line equidistant from the edges of the median separating the main-traveled ways of a divided Interstate Highway, or the centerline of the main-traveled way of a nondivided Interstate Highway.

(c) Controlled portion of the Interstate System means any portion which:

(1) Is constructed upon any part of right-of-way, the entire width of which is acquired for right-of-way subsequent to July 1, 1956 (a portion shall be deemed so constructed if, within such portion, no line normal or perpendicular to the centerline of the highway and extending to both edges of the right-of-way will intersect any right-of-way acquired for right-of-way on or before July 1, 1956);

(2) Lies within a State, the highway department of which has entered into an agreement with the Secretary of Transportation as provided in the act; and

(3) Is not excluded under the terms of the act which provide that agreements entered into between the Secretary of Transportation and the State highway department shall not apply to those segments of the Interstate System which traverse commercial or industrial zones within the boundaries of incorporated municipalities, as such boundaries existed on September 21, 1959, wherein the use of real property adjacent to the Interstate System is subject to municipal regulation or control, or which traverse other areas where the land use as of September 21, 1959, was clearly established by State law as industrial or commercial.

(d) Entrance roadway means any public road or turning roadway, including acceleration lanes, by which traffic may enter the main-traveled way of an Interstate Highway from the general road system within a State, irrespective of whether traffic may also leave the main-traveled way by such road or turning roadway.

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

(f) Exit roadway means any public road or turning roadway including deceleration lanes, by which traffic may leave the main-traveled way of an Interstate Highway to reach the general road system within a State, irrespective of whether traffic may also enter the main-traveled way by such road or turning roadway.

(g) Informational site means an area or site established and maintained within or adjacent to the right-of-way of a highway on the Interstate System by or under the supervision or control of a State highway department, wherein panels for the display of advertising and informational signs may be erected and maintained.

(h) Legible means capable of being read without visual aid by a person of normal visual acuity.

(i) Maintain means to allow to exist.

(j) Main-traveled way means the traveled way of an Interstate Highway on which through traffic is carried. In the case of a divided highway, the traveled way of each of the separated 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.

(k) Protected areas means all areas inside the boundaries of a State which are adjacent to and within 660 feet of the edge of the right-of-way of all controlled portions of the Interstate System within that State. Where a controlled portion of the Interstate System terminates at a State boundary which is not perpendicular or normal to the centerline of the highway, protected areas also means all areas inside the boundary of such State which are within 660 feet of the edge of the right-of-way of the Interstate Highway in the adjoining State.

(l) Scenic area means any public park or area of particular scenic beauty or historical significance designated by or pursuant to State law as a scenic area.

(m) Sign means any outdoor sign, 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 a controlled portion of the Interstate System.

(n) State means the District of Columbia and any State of the United States within the boundaries of which a portion of the Interstate System is located.

(o) State law means a State constitutional provision or statute, or an ordinance, rule, or regulation enacted or adopted by a State agency or political subdivision of a State pursuant to State constitution or statute.

(p) Trade name shall include brand name, trademark, distinctive symbol, or other similar device or thing used to identify particular products or services.

(q) Traveled way means the portion of a roadway for the movement of vehicles, exclusive of shoulders.

(r) Turning roadway means a connecting roadway for traffic turning between two intersection legs of an interchange.

(s) Visible means capable of being seen (whether or not legible) without visual aid by a person of normal visual acuity.