Va. Code § 33.2-102
The cities and towns of the Commonwealth and also the counties that have withdrawn from the provisions of Chapter 415 of the Acts of Assembly of 1932, as amended, may comply fully with the provisions of the present or future federal-aid road acts, and to this end they may enter into all contracts or agreements with the United States government or the appropriate agencies thereof relating to the survey, construction, improvement, and maintenance of roads, streets, and highways under their control and may do all other things necessary to carry out fully the cooperation contemplated and provided for by the present or future acts of Congress relating to the construction, improvement, and maintenance of roads, streets, and highways.
Such localities may also cooperate with the Board in connection with any project for the survey, construction, improvement, or maintenance of any road, street, or highway under their jurisdiction and control that is eligible for federal aid under any present or future federal-aid road acts and may by appropriate agreement or contract authorize the Board to act on their behalf in any dealings necessary with the United States or any agency thereof and may authorize the Board to carry out such survey, construction, improvement, or maintenance work on such projects either with or without participation by the locality. Whenever the Board is given such authority by any such locality, it may do all things contemplated and provided for by present or future federal-aid road acts and the agreements made with such locality.
Va. Code § 33.2-102