The commission may provide, in the proceedings for the issuance of bonds, that the bonds and the interest thereon constitute such lien upon the revenues of the regional transit terminal or any part thereof acquired, constructed, or completed, improved, or extended, by the department as may be provided for in the indenture. The indenture may provide that the bonds shall be secured by the revenues derived from the entire regional transit terminal or from revenues of only certain designated facilities therein.