16 Pa. Stat. § 2611
When any bridge is proposed to be located in any municipality, the county may enter into an agreement with such municipality providing that the municipality shall bear a portion of the cost of the location, laying out, opening, construction and maintenance of such bridge or that the municipality shall provide or maintain the approach thereto within the municipality or bear the costs of property damages of said approach. Every agreement shall be entered into in writing and at least one executed copy thereof shall be furnished to each party thereto. Every such bridge shall be a county bridge and the duty of maintaining the same, except as otherwise herein provided, shall devolve upon the county. The expense thereof shall be provided out of any county funds authorized for use in the maintenance of county bridges.
16 P.S. § 2611