Miss. Code § 65-11-13
The projects upon such county federal aid highway system shall be selected jointly by the several boards of supervisors and the State Highway Commission in conformity with the applicable laws, rules, and regulations of the federal government and the public roads administration, of the federal works agency, or any other authorized agency of the federal government. The order of the construction and completion of such projects shall likewise be determined jointly by the several boards of supervisors and the State Highway Commission in conformity with such laws, rules, and regulations; the State Highway Commission shall first call upon the several boards of supervisors to select and recommend a series of projects in the respective counties in the order in which, in the opinion of the board or a majority thereof, the projects should be constructed. Such selections and recommendations shall be examined and analyzed by the State Highway Commission and, if found to be proper and correct based on the relative use and importance of such roads, shall be approved by the State Highway Commission.
Miss. Code § 65-11-13