 Then PA 88 re-enters Union Township passing several businesses and then becomes Library Road near the Allegheny County line.The entire Allegheny County stretch of PA 88 is also designated as Library Road.Starting at the Washington/Allegheny County line where PA 88 becomes Library Road, PA 88 runs through South Park, Bethel Park, Castle Shannon, and the Overbrook neighborhood of Pittsburgh where PA 88/Library Rd.