If the majority of electors of such counties vote in favor of adopting such master highway development plan and to pay the cost thereof by the issuance of general obligation bonds, the boards of county commissioners of such counties shall proceed to have detailed plans and specifications prepared for all such work. The making of all such improvements under such master county highway development plan shall be thereafter conducted in accordance with the provisions and requirements of section 68-704 of the General Statutes of 1949 and any amendments thereto.