16 Pa.C.S. § 16904: Joint action by counties.

(a) Additional powers.--The provisions of this chapter may also be exercised jointly by adjoining counties as to roads extending along and adjacent to county lines and from one adjoining county into another.

(b) Procedure and jurisdiction.--The procedure and jurisdiction in each county under subsection (a) shall be the same as to any portion of the road lying within the limits of the county, except that the petition, plans and surveys of the road shall describe and exhibit every portion of the road within the limits of the county and every portion of the road extending along the line of or into an adjoining county. The portions of the road lying within limits of each county shall be treated in all proceedings as one continuous road.