constructing a new garage in the northwestern Cook County suburbs at an estimated cost of $60,000,000, (ii) converting the South Cook garage in Markham to a Compressed Natural Gas facility at an estimated cost of $12,000,000, (iii) constructing a new paratransit garage in DuPage County at an estimated cost of $25,000,000, and (iv) expanding the North Shore garage in Evanston to accommodate additional indoor bus parking at an estimated cost of $3,000,000. For the purpose of evidencing the obligation of the Suburban Bus Board to repay any money borrowed as provided in this subsection, the Suburban Bus Board may issue revenue bonds from time to time pursuant to ordinance adopted by the Suburban Bus Board, subject to the approval of the Regional Transportation Authority of each such issuance by the affirmative vote of 12 of its then Directors; provided that the Suburban Bus Board may not issue bonds for the purpose of financing the acquisition, construction, or improvement of any facility other than those listed in this subsection (e). All such bonds shall be payable solely from the revenues or income or any other funds that the Suburban Bus Board may receive, provided that the Suburban Bus Board may not pledge as security for such bonds the moneys, if any, that the Suburban Bus Board receives from the Regional Transportation Authority pursuant to Section 4.03.3(f) of the Regional Transportation Authority Act. The bonds shall bear interest at a rate not to exceed the maximum rate authorized by the Bond Authorization Act and shall mature at such time or times not exceeding 25 years from their respective dates. Bonds issued pursuant to this paragraph must be issued with scheduled principal or mandatory redemption payments in equal amounts in each fiscal year over the term of the bonds, with the first principal or mandatory redemption payment scheduled within the fiscal year in which bonds are issued or within the next succeeding fiscal year. At least 25%, based on total principal amount, of all bonds authorized pursuant to this Section shall be sold pursuant to notice of sale and public bid. No more than 75%, based on total principal amount, of all bonds authorized pursuant to this Section shall be sold by negotiated sale. The maximum principal amount of the bonds that may be issued may not exceed $100,000,000. The bonds shall have all the qualities of negotiable instruments under the laws of this State. To secure the payment of any or all of such bonds and for the purpose of setting forth the covenants and undertakings of the Suburban Bus Board in connection with the issuance thereof and the issuance of any additional bonds payable from such revenue or income as well as the use and application of the revenue or income received by the Suburban Bus Board, the Suburban Bus Board may execute and deliver a trust agreement or agreements; provided that no lien upon any physical property of the Suburban Bus Board shall be created thereby. A remedy for any breach or default of the terms of any such trust agreement by the Suburban Bus Board may be by mandamus proceedings in any court of competent jurisdiction to compel performance and compliance therewith, but the trust agreement may prescribe by whom or on whose behalf such action may be instituted. Under no circumstances shall any bonds issued by the Suburban Bus Board or any other obligation of the Suburban Bus Board in connection with the issuance of such bonds be or become an indebtedness or obligation of the State of Illinois, the Regional Transportation Authority, or any other political subdivision of or municipality within the State, nor shall any such bonds or obligations be or become an indebtedness of the Suburban Bus Board within the purview of any constitutional limitation or provision, and it shall be plainly stated on the face of each bond that it does not constitute such an indebtedness or obligation but is payable solely from the revenues or income as aforesaid.