16 Pa. C.S. § 16707
If a proposed bridge crosses a navigable stream or other public water or the property or right-of-way of any railroad or other public utility requiring the approval of any Federal or State officer, board or body as to the location and construction of the bridge or its approaches, the county shall have authority to construct the bridge in another location and manner as may be necessary to comply with the conditions prescribed by the officer, board or body in granting approval, if the county commissioners deem the proposed bridge necessary for the convenience of the traveling public and accommodates substantially the same traveling public as the bridge would have done if it had been constructed at the location and in the manner originally provided.
16 Pa.C.S. § 16707