53 Pa. Stat. § 1831
The proper authorities of any borough or township or any incorporated town of this Commonwealth, be, and are hereby, authorized to enter into a contract or contracts with the commissioners of any county in this Commonwealth, providing that the said county commissioners shall construct an improved highway or highways under the provisions of the act to which this is a supplement, and the expense or cost of said construction shall be borne jointly by the said borough, township, or incorporated town and the said county, in such ratio or proportions as may be agreed on in said contract or contracts, irrespective of whether the municipality intervenes between two ends of the county highway or not, or whether or not the municipality is the terminus of a county highway, State highway, or township road.
53 P.S. § 1831