Whenever any locality undertakes administration of a transportation improvement project and obtains, in connection therewith, contractor performance bonds that include the Department as a dual obligee, the amount of such bonds shall be no greater than would have been required had the Department not been included as a dual obligee. The surety’s obligation to the Department shall be no greater than its obligation to the locality administering the project, and the amount of the bond is the limit of the surety’s obligation to either or both obligees.