The governing body of such county or city shall cause to be kept separate minutes and records of the operation of such bridge properties available for public inspection, which minutes from time to time shall show the approval or disapproval of the actions of said commission. Concerning the management and operation of said bridge by the commission and the governing body of said city or county, there shall be no obligation on said commission, nor shall there be any general obligation on said city or county, other than from the revenues derived from the operation of said bridge properties and as may be set forth or provided for in the trust indenture or resolution under which the revenue bonds of such governing body were issued for the acquisition of said bridge properties.