36 Pa. Stat. § 670-218
Where any section of any State highway route which contains the terminus of an intersecting State highway route has been or shall be relocated in such a manner that the terminus of the intersecting State highway route does not fall within the limits of the relocated route, the secretary may lengthen or shorten such intersecting route so that its terminus falls within the limits of the relocated State highway route. If the intersecting route is shortened, and the portion thereof abandoned as a State highway be reason thereof is, in the opinion of the secretary, unnecessary for public use and travel, the secretary may vacate said abandoned section. When any State highway route is lengthened under the provisions of this section and property is taken thereby, the damages shall be ascertained and paid as provided by Article III of this act.
36 P.S. § 670-218