The newly constructed five-lane configuration of the road also known as Perry Highway will open to traffic on Wednesday morning, PennDOT District 11 announced.
A northbound lane closure will remain in some areas as needed for work on sidewalks, paving and other activities that will continue as weather allows through winter.
Overall work will conclude in spring 2013.
The $18.1 million project widened Route 19 from 42 feet to 63 feet, adding a center turn lane, curbed gutters and sidewalks. New, improved traffic signals were also added at eight intersections in the project area between Longvue Road, near the top of Pine Creek Hill, and North Chapel/Manor Road.
Additional work included bituminous resurfacing, concrete pavement, drainage, signing, a retaining wall and other improvements.
About 28,000 vehicles use this section of Route 19 on an average day.