Parkway revenue bonds and revenue refunding bonds issued under the provisions of this article shall not be deemed to constitute a debt of the state or of any political subdivision thereof or a pledge of the faith and credit of the state or of any such political subdivision, but such bonds shall be payable solely from the funds herein provided therefor from revenues. All such parkway revenue bonds and revenue refunding bonds shall contain on the face thereof a statement to the effect that neither the state nor any political subdivision thereof shall be obligated to pay the same or the interest thereon except from revenues of the project or projects for which they are issued and that neither the faith and credit nor the taxing power of the state or any political subdivision thereof is pledged to the payment of the principal of or the interest on such bonds.