State highway in Pennsylvania, US
Pennsylvania Route 645 (PA 645) is a state highway in the U.S. state of Pennsylvania. The route runs from U.S. Route 422 (US 422) in Myerstown, Lebanon County north to PA 443 in Pine Grove Township, Schuylkill County. PA 645 heads north from Myerstown into agricultural areas and enters Berks County, where it passes through Frystown and comes to an interchange with Interstate 78 (I-78)/US 22. Past here, the route heads across forested Blue Mountain and continues into Schuylkill County, where it reaches its northern terminus. PA 645 is a two-lane undivided road its entire length. The road was paved for a short distance north of Myerstown by 1928. The paved portion was extended to Frystown in the 1930s and north of there by 1953. PA 645 was designated onto its current alignment in 1962.