The board of commissioners may contract with the authorities of any borough or township, separately or jointly, providing that the commissioners shall construct an improved road in a similar manner as a county road. The expense or cost of said construction shall be borne jointly by the borough, township and the 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 road or not, or whether or not the municipality is the terminus of a county road, State highway or township road.
16 P.S. § 5924