Va. Code § 33.2-1220
The Board may issue regulations and is authorized to enter into agreements with the United States as provided in 23 U.S.C. § 131 with respect to the regulation and control of signs, advertisements, and advertising structures in conformity with § 33.2-1217, provided that such agreements shall not prevent the General Assembly of Virginia from amending or repealing § 33.2-1217 at any time, and provided further that in the event the federal law is amended to lessen the special restrictions applicable to signs, advertisements, and advertising structures adjacent to Interstate System or federal-aid primary highways, the Board is authorized to adopt regulations to conform to such change in federal law and to amend any agreement with the United States relating to such control.
Va. Code § 33.2-1220