The Spaulding Turnpike is a 33.2-mile (53.4 km) north-south toll road in eastern New Hampshire. Nearly its entire length is overlapped by New Hampshire Route 16. Its southern terminus is at the Portsmouth Traffic Circle (Interstate 95 / U.S. Route 1 Bypass) in Portsmouth, a terminus it shares with U.S. Route 4 and NH 16. Its northern terminus is at an interchange with New Hampshire Route 125 in Milton, where NH 16 continues north as a full-access highway. The turnpike roughly parallels the Maine border. NH 16 was signed onto the Turnpike in the mid-1990s.