When such bridge is on the dividing line between two counties which is also the dividing line between one county and a city in the other county and such city has authority to build or rebuild such bridge or to join with any county therein said county may join with said city in the other county in building or rebuilding such bridge. In such case the approval of a grand jury and the court of quarter sessions of the county so joining with a city only shall be required.
16 P.S. § 8554