Revenue bonds issued under this chapter shall be payable exclusively from the funds hereinafter provided therefor from tolls and revenues. All such bonds shall contain a statement on their face that the State is not obligated to pay the same or the interest thereon except from revenues of the project for which they are issued and that the faith and credit of the State are not pledged to the payment of the principal or interest of such bonds. The issuance of revenue bonds under this chapter shall not directly or indirectly or contingently obligate the State to levy or to pledge any form of taxation whatever therefor or to make any appropriation for their payment.