The governing body of the city may enter into an agreement with any competent bank or trust company as trustee for the holders of such bonds, setting forth the duties of the city and the bridge commission in respect to the construction, maintenance, operation and insurance on all funds, the insurance of money on hand or on deposit and the rights and remedies of said trustee and the holders of such bonds, and restricting the individual right of action of bondholders as is customary in trust agreements respecting bonds of corporations. Said trust agreement may contain such provisions for protecting and enforcing the rights and remedies of the trustee and approval by the original bond purchasers of the appointment of consulting engineers and of the security given by the bridge contractors and by any bank or trust company in which the proceeds of bonds or bridge tolls or other money of the bridge commission shall be deposited, and may provide that no contract for construction shall be made without the approval of the consulting engineers. Said trust agreement may further contain provisions and covenants that all or any deposited money shall be secured, as may be therein provided, by surety company bonds or otherwise, and that investments of any or all money shall be prohibited, except as therein provided, or shall be regulated as therein provided, and that insurance upon the bridge and all property connected therewith, also use and occupancy insurance, shall be carried to the extent and under the conditions therein provided. Such trust agreement may also include a covenant that until the revenue bonds secured by such agreement and the interest thereon shall have been paid, the city will charge and collect for transit over any or all other bridges, then or thereafter owned by such city, rates of tolls which may be fixed in such covenant or may be based upon principles and premises set forth in such covenant. The tolls thereafter collected pursuant to such covenant shall be applied as provided in section 14-1226, or for the acquisition or construction or the maintenance and operation, in whole or in part, of any bridge or bridges now owned or hereafter acquired or constructed by such city or as may be otherwise provided by law.