The provisions of this article 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.
The procedure and jurisdiction in each county in such cases shall be the same as to any portion of such road lying within its limits, except that the petition, plans and surveys of such road shall describe and exhibit every portion of such road within the limits of such county and every portion thereof 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.
16 P.S. § 2704