U.S. Route 1 Bypass (Portsmouth, New Hampshire–Kittery, Maine)

U.S. Route 1 Bypass
Route information
Bypass of US 1
Length:	4.3 mi (6.9 km) New Hampshire: 2.756 miles (4.435 km) Maine: 1.6 miles (2.6 km)
Major junctions
South end:	US 1 in Portsmouth, NH
	I‑95 / US 4 / NH 16 / Spaulding Turnpike in Portsmouth, NH
North end:	US 1 in Kittery, ME
Location
Counties:	Rockingham (NH), York (ME)
Highway system
United States Numbered Highways List Bannered Divided Replaced

U.S. Route 1 Bypass is a 4.3-mile (6.9 km) long bypass of U.S. Route 1 in Portsmouth, New Hampshire and Kittery, Maine. Most of its north section, northeast of the Portsmouth Circle where it meets the Blue Star Turnpike (Interstate 95) and Spaulding Turnpike, is built to rudimentary freeway standards, with no cross traffic but driveway access. The southern portion is similarly constructed, although there are two four-way intersections with traffic lights just south of the circle and a third at its south end, just before intersecting with US 1.

Route description

New Hampshire

US 1 Bypass begins at US 1 (Lafayette Road) south of downtown Portsmouth. Formerly a half-interchange with limited access and a flyover ramp, the old interchange was converted to a standard three-way intersection with full access in 2013. US 1 Bypass heads northwest (with NH 33 passing over without an interchange) and continues to the west of the city. It has two at-grade intersections with Borthwick Avenue and Coakley Road/Cottage Street before it comes to a large rotary, the Portsmouth Traffic Circle, where it interchanges with Interstate 95 and the southern end of the Spaulding Turnpike/NH 16 (which is also the eastern terminus of U.S. Route 4). US 1 Bypass enters the circle from the southeast and leaves via the first exit, turning to the northeast towards Maine.

Upon leaving the rotary, US 1 Bypass immediately interchanges with Woodbury Avenue, which provides access to downtown and directly serves the retail district of Newington. The highway continues to the northeast, interchanging with Maplewood Avenue, and crossing over Market Street (no interchange) before reaching the Piscataqua River and crossing the Sarah Mildred Long Bridge into Kittery, Maine. This bridge, built in 1940, is a lift bridge maintained by the Maine-New Hampshire Interstate Bridge Authority.

Maine

Upon crossing into Maine, US 1 Bypass interchanges with Bridge Street (northbound) and Oak Terrace (southbound), local roads which provide a connection to State Route 103. US 1 Bypass crosses over SR 103, but does not directly interchange with the highway. The remaining stretch of highway up to the junction with US 1 ceases to be limited-access, with local businesses and parking lots straddling the roadway. The final exit on the bypass connects to US 1 and SR 236. This ramp best serves SR 236 northbound, which connects to I-95, and US 1 southbound for drivers destined for southern Kittery, Badgers Island, or returning to Portsmouth. The mainline of US 1 Bypass merges directly onto US 1 northbound, which provides a direct connection to I-95 North and the Maine Turnpike. US 1 Bypass southbound has exits for I-95 south and north as well as SR 236 at the northern terminus.

Major intersections

State	County	Location	mi	km	Destinations	Notes
New Hampshire	Rockingham	Portsmouth	0.000	0.000	US 1 (Lafayette Road)	Southern terminus of US 1 Bypass
			1.413	2.274	To US 4 / NH 16 to Spaulding Turnpike – Concord, Rochester To I‑95 – Maine, Massachusetts	Portsmouth Traffic Circle; I-95 exit 5 Southern terminus of NH 16, eastern terminus of US 4
Piscataqua River			2.756 0.0	4.435 0.0	Sarah Mildred Long Bridge New Hampshire–Maine state line
Maine	York	Kittery	0.3	0.48	To SR 103 / Bridge Street – Navy Yard, Eliot
			1.2	1.9	SR 236 / US 1 south to I‑95 south – Kittery Point, Eliot, South Berwick	Northbound exit/southbound entrance
			1.6	2.6	US 1 north to I‑95 north / Maine Turnpike	Northern terminus of US 1 Bypass
1.000 mi = 1.609 km; 1.000 km = 0.621 mi       Incomplete access