Rest Stop Interstate 81 Approx Mile Marker 402 rest stops, one northbound, one southbound. They are about 1/2 mile apart. Coming southbound down from Harrisburg, PA, you pass Carlisle exits, the Plainfield exit, then the rest stop is about 41-40 mile marker. The slanted parking spaces easily park 75 State: Pennsylvania City: Carlisle PA – Newville PA Nearest Town: Interstate 81 – Newville PA – Carlisle PA Status; Unknown Cost: Free Nearest Road: Paved Scenery Rating: 3 Months Opened: -