Va. Code Ann. § 33.2-317

The highways embraced within the primary state highway system shall be established, constructed, and maintained exclusively by the Commonwealth under the direction and supervision of the Commissioner of Highways, with such state funds as may be appropriated and made available for such purposes, together with such appropriations as may be made by any county, district, city, or town in the Commonwealth and such funds as are available or derived from the federal government for highway building and improvement in the Commonwealth.