Interstate 91 (abbreviated I-91) is an Interstate Highway in the New England region of the United States. It provides the primary north-south thoroughfare in the western part of New England. The interstate's southern end is in New Haven, Connecticut at Interstate 95; its northern end is at Derby Line, Vermont, a village in the town of Derby, at the Canadian border, where it continues as Autoroute 55. The largest cities along its route are New Haven, Hartford and Springfield, Massachusetts.

Interstate 91 is long and runs nearly straight north and south: in Connecticut; in Massachusetts; and in Vermont. (The net displacement is 259 miles (417 km), and the net direction is 9.0 degrees clockwise from north or south, i.e., northeast by north or southwest by south.) I-91 parallels U.S. Route 5 for most of its length, and many of the exits along I-91 provide direct or indirect access to the older route.

Much of the route of Interstate 91 follows the Connecticut River, running from Hartford, Connecticut northward to St. Johnsbury, Vermont.

Route description

Connecticut

Interstate 91 is the major north-south transportation corridor for the center of the state. It is the main route between the larger cities of New Haven, Hartford, and Springfield, MA. As such, it is almost always heavily trafficked (especially during rush hour), and maintains at least three lanes in each direction through Connecticut. The three cities also serve as Connecticut's control points along its length of the Interstate. Overhead signs in each direction consistently feature one or two of the cities, although very few (if any) conventional highway mileage signs are placed along the Interstate in Connecticut that indicate the remaining distance between the cities.

The highway begins just east of downtown New Haven at the intersection with the Connecticut Turnpike Interstate 95 and Connecticut Route 34. At the bottom of the ramp for Exit 5, U.S. Route 5 has its southern terminus and the first of its many interchanges with the freeway. Leaving New Haven, I-91 follows a northeastward trek through New Haven's suburbs of North Haven and Wallingford before entering the city of Meriden. In Meriden, about halfway between Hartford and New Haven, I-91 sees an interchange with its first spur route, Interstate 691. I-691 provides a westward link to Interstate 84 and the city of Waterbury. Leaving Meriden, I-91 travels briefly through Middletown before passing through Cromwell, Rocky Hill, and Wethersfield, eventually entering the Hartford city limits. Just south of Hartford, the highway begins to directly parallel the Connecticut River. In Hartford, I-91 interchanges with I-84 before leaving the city limits. I-91 will maintain an urban character throughout its distance to Springfield. Halfway between the two cities, Exit 40 provides direct access (via Connecticut Route 20) to the Bradley International Airport. I-91 runs through Windsor, Windsor Locks, East Windsor, and Enfield (with several exits in each town) before crossing into Massachusetts at milepost 58.

I-91's final exit in Connecticut is Exit 49, which offers northbound travelers access to Longmeadow, MA, after which I-91 enters Massachusetts.

Massachusetts

Interstate 91 travels through the Pioneer Valley of western Massachusetts paralleling the Connecticut River. I-91 serves as the major transportation corridor through three Massachusetts counties, linking the cities of Springfield, Northampton, and Greenfield. The three cities serve as the control cities listed on guide and mileage signs, along with Brattleboro, VT beginning with the first northbound conventional mileage sign () in Longmeadow.

In Springfield, I-91 intersects with Interstate 291 at Exit 6, a spur going eastbound connecting with the Massachusetts Turnpike, primarily for travelers going on the Turnpike eastound to Worcester and Boston.

North of Springfield, I-91 briefly enters Chicopee itself where there is an interchange with the spur of Interstate 391 before turning westward to cross the Connecticut River into West Springfield. I-391 provides direct access to Holyoke center, while I-91 continues on the western side of the river.

Just after the river crossing, Exit 14 is a major interchange with the Massachusetts Turnpike (I-90) before entering the city of Holyoke where Exit 15 is located. Just after Exit 16 U.S. 202, I-91 goes from six lanes to four lanes in each direction to the Vermont state line.

After a short exit-less stretch, I-91 enters Northampton and has a few more interchanges. The towns of Hadley and Amherst, home to the main campus of the University of Massachusetts, are accessible from I-91 exits in Northampton via Route 9.

Continuing north, I-91 enters Hatfield, and where it begins its straightest section — nearly without a bend in the road. Several exits provide access to U.S. Route 5 and Massachusetts Route 10 in Hatfield and Whately before entering Deerfield.

I-91 has two exits in Greenfield. At Exit 26, there is a rest area/visitor information center for Franklin County. Exit 28 in Bernardston is the last exit in Massachusetts. Beyond exit 28, I-91 continues for about more before crossing into Vermont.

The stretch of I-91 in Massachusetts is the only section to feature motorist-aid call boxes. The call boxes are still important, as a good part of I-91 in Massachusetts is rural, unlike many other freeways in the state. Massachusetts is the only state traversed by Interstate 91 where another numbered highway is co-signed onto the Interstate (in this case, U.S. 5, for a spur near the Springfield-Longmeadow town line and MA 2, for approximately in Greenfield).

Vermont

Interstate 91 runs along the eastern border of Vermont and serves as a major transportation corridor for both Vermont and western New Hampshire. Many exits along Vermont's length of I-91 feature New Hampshire towns on the guide signs (for example, Exit 3, which lists Brattleboro and Keene, NH, as the points of access). Interstate 91 is in Vermont and is two lanes in each direction the entire way from the Massachusetts state line at Guilford to Derby Line, nearly two-thirds of the Interstate's total length, with 29 interchanges. The highway's rural character and long distances between exits in Vermont are in stark contrast to that of its length in Connecticut and the greater Springfield, MA area where exits are more frequent and the road carries four lanes of traffic in each direction at some points. The major control "cities" are Brattleboro, White River Junction, St. Johnsbury, and Newport. When re-entering I-91 North at Exit 28 in Derby, Vermont the control sign is for Canada. Of these, only Newport is a city, although the others are fairly sizable towns. The road generally parallels its predecessor, US 5.

I-91 enters Vermont in the town of Guilford. Just before Exit 1 in Brattleboro is the Vermont Welcome Center & Rest Area, which has a staffed Tourist Information Center.

The first 3 exits are all located in the town of Brattleboro. Rt 5 North from Exit 1 provides access to a number of stores and a small industrial area before reaching the south end of the town's center, then continuing on across the Connecticut River to Hinsdale, NH. Exit 2/Route 9 provides access to the western village of the town (also known as West Brattleboro) and a covered bridge which leads to the town's Memorial Park. Rt 9 then continues West to Marlboro and Bennington.

Exit 3 is considered to be one of the busiest exits along I-91 in Vermont. Brattleboro's main retail strip is located here, including a supermarket, several "chain" stores, a multi-screen movie theater, several nice restaurants, hotels / motels and some fast-food outlets. Following Vermont Route 9 eastward, one can reach Keene in .

After Exit 3, I-91 heads out of Brattleboro to pass through the towns of Dummerston, Putney, Westminster, Rockingham, Springfield, Weathersfield, Windsor, Hartland, and White River Junction. White River Junction, listed as a control city on mileage signs as far south as Greenfield, MA, is where I-91 and I-89 meet and provide access to many points in Vermont and New Hampshire. Motorist services like hotels and restaurants, as well as many stores, are available in both states near the intersection of the Interstate Highways. North of the interchange with I-89, I-91 continues towards St. Johnsbury and passes through the towns of Norwich, Thetford, Fairlee, Bradford, the village of Wells River in the town of Newbury, and the town of Barnet before coming to its next major intersection. Towns in New Hampshire on the other side of the river can also be easily accessed in this stretch. At Exit 19, is the northern terminus of Interstate 93, a major interstate highway in New England, which provides a direct route through the White Mountains and to almost all major cities in New Hampshire. Just after Exit 19, there are three exits for St. Johnsbury, including a major intersection with U.S. Route 2. Along westbound U.S. 2, the capital of Vermont, Montpelier, is eventually reached from I-91, although I-89 provides Montpelier with immediate Interstate access.

Interstate 91 continues northward, now following the Passumpsic River Valley. It passes through the center of Vermont's Northeast Kingdom and the towns of Lyndon. Two exits in Lyndon serve the village of Lyndonville and Lyndon State College. Here for the first time, I-91 departs after exit 24, from closely paralleling Route 5 which turns eastward. I-91 follows Miller Run Valley. Therefore there are no convenient services until Barton at exit 25.

The interstate proceeds through Sheffield. Here it reaches the highest point on the road, just north of mile marker 150 on Sheffield Heights, .

After leaving the Heights, it enters Orleans County and follows the Barton River Valley north through Barton, Orleans and Derby. A full range of services is available at Exit 28 in Derby, VT. Exit 29 is the final U.S. exit on I-91 just after mile marker 177 in Derby Line. Beyond the exit ramp, northbound motorists enter Canadian customs at Stanstead, Quebec and continuing into Canada as Autoroute 55 through the Eastern Townships. To reverse direction without crossing the border, motorists must use Exit 29 to re-enter I-91 southbound. Caswell Avenue, if followed westward for a mile, intersects with U.S. Route 5 at its northern terminus.

As with Connecticut and Massachusetts, U.S. 5 closely parallels Interstate 91 for their entire lengths in Vermont. Indeed, most of the large exit signs on I-91 list U.S. 5 as one of the roads (if not the only road) that can be accessed from the exit, as seen in the exit list below. While paralleling I-91 in Vermont, U.S. 5 is never co-signed onto the freeway, but remains its own two-lane road.

Traffic (and the population of each successive town) tend to diminish as the road proceeds northwards. Average daily traffic count for 2002 were — Brattleboro (25,600), White River Junction (28,900), St. Johnsbury (10,800), and Derby Line (2,500).

History

In the 1970s there were plans to extend I-91 across the Long Island Sound from New Haven, Connecticut to Long Island in New York. The extension would continue south to the southern shore of the island perhaps along the route of the current William Floyd Parkway in central Suffolk County. It would also provide easier access to New York City via the Long Island Expressway, as well as to The Hamptons via Sunrise Highway (New York State Route 27).

After the September 11 attacks there has been a seldom-manned temporary border patrol checkpoint near White River Junction, VT that is about from the US-Canada border in an effort to stop terrorism.

Starting in the 1990s, several rest areas were downgraded in Vermont, increasing distances between facilities. In 2008, Vermont closed the Springfield-Rockingham rest areas because of suspected use by drug abusers. In 2009, the northbound rest area in Hartford was closed, creating a 90 mile gap in on-highway facilities. At the present time, there exist 2 intermediate rest areas with facilities in each direction, in addition to a welcome center at each end of the state. Several parking areas remain open.

Exit list

Connecticut

Massachusetts

Vermont

Auxiliary routes