53 Pa. Stat. § 22777
The city planning commission of such cities is empowered, after it shall have adopted a major street plan of the city or any section or part of it, to make or cause to be made from time to time surveys for the exact location of the lines of a new street or streets, or for the relocation or widening of existing streets, in any portion of such territory, and to make a plat of the area or district thus surveyed showing the land which it recommends be reserved for future acquisition for public streets. The commission, before adopting any plat, shall hold a public hearing thereon, notice of the time and place of which, with a general description of the district or area covered by the plat, shall be published once not less than ten days previous to the time fixed therefor. After such hearing the commission may transmit the plat as originally made, or modified as may be determined by the commission, to council, together with the commission's estimates of the time or times within which the lands shown on the plat as street locations should be acquired by the city. Thereupon by ordinance council may approve and adopt, or may reject, such plat, or may modify it with the approval of the planning commission, or, in the event of the planning commission's disapproval, council may, by a majority vote of its entire membership, modify such plat and adopt the modified plat. In the ordinance of adoption of a plat council shall fix the period of time for which such street locations shall be deemed reserved for future taking or acquisition for public use. Such approval an adoption of a plat shall not, however, be deemed the opening or establishment of any street, nor the taking of any land for street purposes, nor for public use, nor as a public improvement, but solely as reservation of the street locations shown thereon, for the period specified in the ordinance, for future taking or acquisition for public use. The commission may at any time negotiate for or secure from the owner or owners of any such lands releases of claims for damages or compensation for such reservations, or agreements indemnifying the city from such claims by others, which releases or agreements shall be binding upon the owner or owners executing the same and their successors in title. After a plat is so adopted it may be changed by council to conform to a new plat prepared by the commission after a hearing similar to that required in the case of the original plat. At any time council may by ordinance abandon any reservation.
53 P.S. § 22777