In counties of the third, fourth, fifth, sixth, seventh and eighth class, if a bridge is to take the place of an existing bridge, the viewers may change the location of the bridge so that it may be located and built in the most suitable place, or at the least expense, or in the best manner, and, for the change of location of the bridge, the county commissioners shall report what change in the course or bed of the road connected with the bridge will be necessary, and shall also report the vacation of the old or existing bridge, and the vacation of the portion of the road connecting with the bridge as the county commissioners deem proper.
Pennsylvania Legal Code