(1) Subject to public notice as provided in s. 348.54, the authority is authorized to provide by resolution for the issuance from time to time of bonds pursuant to s. 348.56(1)(b) for the purpose of refunding any bonds then outstanding regardless of whether the bonds being refunded were issued by the authority pursuant to this chapter or on behalf of the authority pursuant to the State Bond Act. The authority is further authorized to provide by resolution for the issuance of bonds for the combined purpose of:
(a) Paying the cost of constructing, reconstructing, improving, extending, repairing, maintaining and operating the expressway system.
(b) Refunding bonds then outstanding. The authorization, sale and issuance of such obligations, the maturities and other details thereof, the rights and remedies of the holders thereof, and the rights, powers, privileges, duties and obligations of the authority with respect to the same shall be governed by the foregoing provisions of this part insofar as the same may be applicable.
(2) In the event that the authority shall determine to issue bonds for the purpose of refunding any outstanding bonds prior to the maturity thereof, the proceeds of such refunding bonds may, pending the redemption of the bonds to be refunded, be invested in direct obligations of the United States. It is the express intention of this part that outstanding bonds may be refunded and retired by and upon the issuance of bonds notwithstanding that all or a portion of such outstanding bonds will not mature or become redeemable until after the date of issuance of such refunding bonds.