New Hampshire Highway System
|New Hampshire Highway System|
Standard marker for New Hampshire Routes, featuring the Old Man of the Mountain
|Length:||4,814 mi (7,747 km)|
|Notes:||NHDOT maintains 17,029 mi (27,406 km) of roads in total|
|Interstates:||Interstate n (I-n)|
|US Routes:||U.S. Route n (US n or Route n)|
|State:||New Hampshire Route n (Route n)|
New Hampshire Routes
The New Hampshire Highway System is the public roads system of the U.S. state of New Hampshire containing approximately 17,029 miles (27,406 km) maintained by the New Hampshire Department of Transportation (NHDOT). All public roads in the state are called "highways", thus there is no technical distinction between a "road" or a "highway" in New Hampshire.
The state maintains 4,814 miles (7,747 km) of roads, of which 2,567 miles (4,131 km) are numbered routes and 1,465 miles (2,358 km) are unnumbered roadways making up the State's secondary roadway system. The state has 557 miles (896 km) of primary highways, which it defines as highways that "connect population centers, other NHS routes within the state, and other NHS routes in the surrounding states: Vermont, Maine, and Massachusetts." The remaining 12,215 miles (19,658 km) of roads are maintained typically by the towns and cities traversed by these roads.
Highways assigned a number by the NHDOT are officially known as "New Hampshire Route X", often abbreviated "NH Route X" or simply "Route X".
Many minor state highways are not assigned numbers, only local names.
In March 2011, New Hampshire ranked amongst the top ten "Best" states in the American State Litter Scorecard, for overall effectiveness and quality of its public space cleanliness—-primarily roadway and adjacent litter--from state and related debris removal efforts. 
Interstate highways 
A total of 224.2 miles (360.8 km) of roadway in New Hampshire are part of the Interstate Highway system.
- Three primary Interstates pass through New Hampshire: Interstate 89, Interstate 93, and Interstate 95.
- Two secondary Interstates are located in New Hampshire, Interstate 293 and Interstate 393.
Turnpike system 
The NHDOT Bureau of Turnpikes is responsible for maintenance of the public toll roads in New Hampshire:
- Frederick E. Everett Turnpike (also known as the Central Turnpike), which runs from the Massachusetts state line in Nashua north to Concord. It is routed along parts of U.S. Route 3, Interstate 293, and Interstate 93. It runs by itself between US-3 in Nashua and I-293 in Manchester, the only turnpike in New Hampshire not completely overlapped with another route. The turnpike is unsigned along its concurrency with I-93.
- Eastern Turnpike, which is composed of the following two connecting turnpikes:
- Blue Star Turnpike (also known as the New Hampshire Turnpike) runs 14.3 miles from the Massachusetts border in Seabrook north to the Portsmouth Traffic Circle, where it connects with the southern end of the Spaulding Turnpike. The Blue Star Turnpike comprises most of Interstate 95's length in New Hampshire (minus the extension north into Maine) and is signed solely as I-95.
- Spaulding Turnpike, which begins at an interchange with I-95 in Portsmouth and runs northward along the Maine state line to Milton. Formerly a lone route, Route 16 was routed over all but the southernmost 0.8 miles of the Turnpike. U.S. Route 4's easternmost stretch is also routed over the southern section of the Turnpike, between I-95 and Exit 6.
National Highway System 
782 miles (1,259 km) of state-maintained roads are a part of the National Highway System (NHS). Of the NHS roads in the state, 225 miles (362 km) are Interstate highways (35 miles of which are also on the New Hampshire Turnpike System; 52 miles (84 km) of non-interstate turnpike highways; and 505 miles (813 km) of non-interstate and non-turnpike highways.
Classification of state highways 
New Hampshire RSA 229:5 Classification. sets out the seven different classes of highways in the state:
- Class I – all portions of the turnpikes and the national system of interstate and defense highways, and all existing or proposed highways on the primary state highway system, excepting all portions of highways within the compact sections of the cities and towns listed in RSA 229:5, V., which aren't part of the state or national turnpike system or are defense highways
- Class II – all existing or proposed highways on the secondary state highway system, excepting all portions of such highways within the compact sections of the cities and towns listed in RSA 229:5, V.
- Class III – all recreational roads leading to, and within, state reservations designated by the General Court
- Class III-a – boating access highways from any existing highway to any public water in this state.
- Class IV – all highways within the compact sections of cities and towns listed in RSA 229:5, V., which are not Class I or II highways
- Class V – all other traveled highways which a town has the duty to maintain regularly and shall be known as town roads
- Class VI – all other existing public ways, including all highways discontinued as open highways and made subject to gates and bars, except Class III-a roads, and all highways which have not been maintained and repaired by the town for travel thereon for 5 or more successive years
Under RSA 229:5, V. the Commissioner of Transportation may establish compact sections in the following cities and towns:
Routes crossing state lines 
Two New Hampshire state routes actually cross state lines while retaining their designations:
- New Hampshire Route 113B, which is actually a loop of Maine State Route 113, is the only New Hampshire highway to cross entirely into Maine while remaining a New Hampshire route.
- New Hampshire Route 153, part of which runs directly on the Maine-New Hampshire state border for a short distance, touches the state of Maine but does not cross the border entirely.
Signage practices 
State highways 
State highways in New Hampshire are marked using square route shields depicting the Old Man of the Mountain. Unlike its neighboring states, New Hampshire does not use elongated shields for route markers, but uses condensed fonts for three-digit routes instead. Alternates of two- and three- digit routes (e.g. Route 113B) are signed with the parent highway's number over the letter of the alternate. New Hampshire also has one 'bypass' state route, Route 28 Bypass, which is marked with a standard Route 28 shield, except with the word 'BYPASS' over the numeral. Route 101 has its own business route, and its alternate, Route 101A, has its own bypass, but these routes are very poorly signed, if only on guide signs.
U.S. highways 
New Hampshire uses the standard issue U.S. Route shield, a six-point white shield over a black square background. New Hampshire does not use elongated route shields for U.S Routes, except on the occasional guide sign from a freeway. Alternates of U.S. Routes in New Hampshire are signed as state routes, with two exceptions: U.S. Route 1 Bypass and U.S. Route 3 Business. US-1 Bypass is signed in a similar fashion to Route 28 Bypass, a standard US-1 shield with the word 'BY-PASS' over the numeral. US-3 Business is unsigned, as it is completely overlapped by other routes.
Interstate highways 
New Hampshire uses standard size Interstate shields for its two-digit Interstate highways. Elongated shields were not initially used for auxiliary Interstates, but such shields are appearing on newer signage. New Hampshire no longer uses its state name on Interstate shields, but older signs with the state name are still prevalent.
Route concurrencies 
New Hampshire has an unusual way of signing route concurrencies. Rather than separate shield assemblies for each route, concurrencies are signed on green signs, similar to those found on freeway guide signs. These signs are also used for signing junctions with other routes, regardless of whether there is a concurrency. These particular sign assemblies are, however, lacking in cities.
Numbered state highways 
Unnumbered state highways 
Several unnumbered roads also are maintained by the state, including:
- The Circumferential Highway in Nashua & Hudson (the portion that is built)
- Daniel Webster Highway in South Nashua
See also 
- Spacek, Steve (March 13, 2011). "American State Litter Scorecard: New Rankings for an Increasingly Environmentally Concened Populace". American Society for Public Administration Conference. Retrieved March 6, 2012.