Whenever appropriations are made by the legislature for the construction or reconstruction of any highway or portion thereof, the director of transportation, in the absence of any provisions to the contrary in the act making the appropriation or in any other state laws applicable thereto, and in case the highway is eligible for federal aid and the director deems such course advisable, may, subject to the approval of the administrator, construct such highway as a federal-aid project and contract for it in accordance with the provisions of this part and of the Federal Highway Act. If any appropriation made by the legislature for the construction or reconstruction of any highway or any portion thereof is required by the act making the appropriation to be expended by the council of a particular county, the director may, in the absence of any specific provision to the contrary in the act making such appropriation, subject to the approval of the governor, designate such highway as a federal-aid project; and the council, upon that designation, shall place the appropriation in the control and at the disposal of the director for the purpose of constructing the highway or portion thereof as a federal-aid project, and the director shall proceed to construct such highway as a federal-aid project and to contract for it in accordance with this part and the Federal Highway Act.