The State Highway Commission shall notify the board of supervisors of each county of the amount of money to be available for expenditure in such county from said federal apportionment, and of the amount of money available from the appropriation made to the State Highway Fund as the state’s share of the federal aid program on secondary and feeder roads. Within three months after the receipt of such notice, the board of supervisors of each county shall submit to the State Highway Commission a description of the recommended projects on county highways in such county which are approved by the county and recommended for selection and designation for participation in federal aid under the Federal Aid Highway Act of 1944 [58 U. S. Stat. 838, ch. 626]. In the selection of such projects and in the recommendation of the order of their improvement, the boards of supervisors shall select projects which will be of the greatest benefit to the county as a whole, judged from the standpoint of relative use and importance, without regard to district or beat lines, insofar as same is consistent with the rules and regulations of the public roads administration of the federal works agency. All such projects and the order of their inauguration shall be subject to the approval of the State Highway Commission as provided in Section 65-11-13.