(a) In the discretion of the commissioner, any railroad maintenance bonds or notes or railroad maintenance refunding bonds issued by them under this article may be secured by a trust agreement between the commissioner and a corporate trustee, which trustee may be any trust company or banking institution having the powers of a trust company within or without this state.

(b) Any such trust agreement shall pledge or assign revenues of the State Rail Section to be received, but shall not convey or mortgage any railroad project in whole or in part. Any such trust agreement or any authorization providing for the issuance of such bonds or notes may contain such provisions for protecting and enforcing the rights and remedies of the bondholders or noteholders as are reasonable and proper and not in violation of law, including covenants setting forth the duties of the division in relation to the acquisition of property, the construction, improvement, maintenance, repair, operation, and insurance of the railroad project in connection with which such bonds or notes are authorized, the rentals or other charges to be imposed for the use or services of any railroad project, the custody, safeguarding, and application of all moneys and provisions for the employment of consulting engineers in connection with the construction or operation of such railroad project. Any banking institution or trust company incorporated under the laws of this state which may act as depository of the proceeds of bonds or notes or of revenues shall furnish such indemnifying bonds or pledge such securities as are required by the division. Any such trust agreement may set forth the rights and remedies of the bondholders and noteholders and of the trustee and may restrict individual rights of action by bondholders and noteholders as customarily provided in trust agreements or trust indentures securing similar bonds. Such trust agreement may contain such other provisions as the commissioner deems reasonable and proper for the security of the bondholders or noteholders. All expenses incurred in carrying out the provisions of any trust agreement may be treated as a part of the cost of the operation of the railroad project. Any trust agreement or authorization of the issuance of railroad maintenance revenue bonds may provide the method whereby the general administrative overhead expenses of the division shall be allocated among the several projects acquired or constructed by it as a factor of the operating expenses of each such project.