Pennsylvania Route 31 is a 74-mile-long (119 km) state highway located in Western Pennsylvania, paralleling U.S. Route 30 and the Pennsylvania Turnpike for most of its length. The designation begins at PA 136 near West Newton and ends at US 30 near Bedford.

U.S. Route 30 (US 30) is a U.S. Highway that runs east–west across the southern part of Pennsylvania, passing through Pittsburgh and Philadelphia on its way from the West Virginia state line east to the Benjamin Franklin Bridge over the Delaware River into New Jersey.