(a) If appropriate matching federal funds are available to this State under the federal Highway Beautification Act of 1965 and the Federal-Aid Highway Amendment of 1974, the Administration shall acquire, by purchase, gift, or condemnation, and remove any outdoor sign that, on July 1, 1975, lawfully existed along or near any federal-aid primary highway and that does not comply with this part.
(b) In controlling outdoor signs adjacent to federal-aid primary highways under the federal Highway Beautification Act of 1965, the Federal-Aid Highway Amendment of 1974, and any related agreement between the Administration and the federal government, the Administration is not required to remove any sign that advertises a natural wonder or a scenic or historical attraction, if the sign conforms to national standards for such signs under Title 23 of the United States Code.