53 Pa. Stat. § 1861
Whenever any street, alley, or highway more than one-half the width of which is within the limits of any city, borough, or township shall divide the said city, borough, or township from any other municipality or township located within the same county, such street, alley, or highway may be improved by the city, borough, or township within which the greater width is located in the same manner as if the said street, alley, or highway were entirely located within the limits of said city, borough, or township.
The property abutting on the side of said street, alley, or highway which is located outside the limits of the city, borough, or township making such improvements shall, for a depth of one hundred and fifty feet plus one-half the width of said street, alley, or highway from its center line, be assessed for any and all municipal improvements to or on the said street, alley, or highway in the same manner as such property would be assessed under the laws of the Commonwealth if it were entirely located within the limits of such city, borough, or township.
53 P.S. § 1861