16 Pa. C.S. § 16711
If a bridge is proposed to be located in a municipality, the county may enter into an agreement with the municipality if the municipality bears a portion of the cost of the location, laying out, opening, construction and maintenance of the bridge or that the municipality provides or maintains the approach to the bridge within the municipality or bears the costs of property damages of the approach. Each agreement shall be entered into in writing and at least one executed copy of the agreement shall be provided to each party. Each bridge shall be a county bridge and, except as otherwise provided, be maintained by the county. Maintenance expenses shall be provided out of county funds authorized for use in the maintenance of county bridges.
16 Pa.C.S. § 16711