53 Pa. Stat. § 1725
All cities in this commonwealth shall have power, without petition of property owners, to grade, pave, curb, macadamize, and otherwise improve any public street or public alley, or part thereof, within their corporate limits: Provided, The ordinance or ordinances authorizing and directing such improvement shall be adopted and enacted by the affirmative vote of three-fourths of the members elect composing the councils of the said cities, and shall be approved by the mayor or city recorder thereof. No such ordinance shall be finally adopted and enacted in a less period than thirty (30) days from the date of its introduction, and in the meantime copies of said ordinance shall be published in each of the official newspapers of such cities, once a week for three consecutive weeks, immediately following the introduction thereof, and in the event such cities shall have no official newspapers, then in at least two weekly newspapers, published in the county in which the cities are situate, once a week for three consecutive weeks.
53 P.S. § 1725