36 Pa. Stat. § 670-208
No person shall be entitled to recover any damages for any buildings or improvements of any kind which shall or may be placed or constructed upon or within the ultimate widths and lines of any State highway after the same shall have been established for future construction and recorded as aforesaid.
No person shall be entitled to damages by reason of such establishment of the ultimate width and lines of a State highway for future construction; and, where the Commonwealth, by its proper authorities, has improved or constructed or shall hereafter improve or construct such State highway and, in so doing, has taken or shall take a part only of the lands lying within the lines shown by such plan, damages shall be allowed for and to the extent of such actual taking only. Such taking shall be deemed to occur only when right of way plans or construction drawings, prepared by the department, showing thereon the right of way required for highway purposes and for slopes, shall have been approved by the secretary and the Governor and filed as a public record in the office of the department.
36 P.S. § 670-208