Interstate 81 forms a major north–south corridor through the state of Pennsylvania, serving the boroughs of Chambersburg and Carlisle, where it meets the Pennsylvania Turnpike. But I-81 does not directly interchange with it (motorists must use US 11 to connect). Around the state capital of Harrisburg, the route forms the northeastern section of Pennsylvania's Capital Beltway. The route then travels northeast toward the Wyoming Valley, where it serves the cities of Wilkes-Barre and Scranton, then heads north through the Endless Mountains region toward the state line. Although it is signed as a north–south highway, it is distinctly northeast–southwest and occasionally east–west throughout the state.