The route runs for 2.7 miles ( 4.3 km ) in New Hampshire , and is mostly a four - lane divided semi-limited access freeway .
Two four - way traffic signals are present south of the Portsmouth traffic circle .
The route runs for 2.7 miles ( 4.3 km ) in New Hampshire , and is mostly a four - lane divided semi-limited access freeway , although two four - way traffic signals are present south of the Portsmouth traffic circle .