The treasurer of any county issuing bonds as aforesaid shall create a fund to be known and designated as the county highway sinking fund, and on the first day of July of each and every year in which a parcel of the bonds sold pursuant to the provisions of this article shall become due, shall transfer from said general fund to said county highway sinking fund such amount of money as may be required to pay the principal of the bonds so becoming due and payable in such years. As the same becomes due, the principal of all such bonds sold shall be paid from such county highway sinking fund, and as the same becomes due the interest on all bonds sold shall be paid from said interest fund. Both principal and interest shall be paid upon warrants drawn by the board of county commissioners upon the county treasurer, and the faith of the county issuing any such bonds shall be pledged for the payment of the principal of said bonds so sold and the interest accruing thereon.