The governing body of the county 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 county in respect to the construction, maintenance and operation, and insurance of any such bridge, the conservation and application of all funds, the insurance of money on hand or on deposit, the rights and remedies of the 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. The 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 shall be deposited, and may provide that no contract for construction or purchase shall be made without the approval of the consulting engineers. The 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, except as therein provided, or shall be regulated as therein provided, and that insurance upon the bridge and all property connected therewith, and also use and occupancy insurance, shall be carried to the extent and under the conditions therein provided.