Interstate 91

I-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, Massachusetts. As such, it is almost always heavily trafficked (especially during rush hour), and maintains at least three lanes in each direction through Connecticut except for a short portion in Hartford at the interchange with I-84 and in Meriden at the interchange with Route 15. The three cities also serve as Connecticut's control points along its length of the Interstate.[8][9]

I-91 begins just east of downtown New Haven at an interchange with I-95 (the Connecticut Turnpike), and Route 34. At the bottom of the ramp for exit 5, US 5 begins at the first of its many interchanges with the freeway.[10] Leaving New Haven, I-91 follows a northeastward trek into North Haven, where it meets the southern end of the Route 40 expressway.[11] It travels through the eastern part of Wallingford before entering the eastern part of the city of Meriden. In Meriden, about halfway between Hartford and New Haven, I-91 sees a complex set of interchanges with the Wilbur Cross Parkway (Route 15), the Route 66 expressway, and its first spur route, I-691.[10] I-691 provides a westward link to I-84 and the city of Waterbury.[10] Leaving Meriden, I-91 enters Middlesex County as it briefly travels through the western part of Middletown before entering Cromwell, where it has an interchange with the Route 9 expressway.[12][13]

It then enters Hartford County in the town of Rocky Hill, and then enters Wethersfield, where it meets the southern end of the Route 3 expressway, which leads to Glastonbury and the Route 2 expressway via the Putnam Bridge over the Connecticut River. From here to St. Johnsbury, Vermont, I-91 parallels the river, never more than five miles (8.0 km) from its shore.[14] I-91 then enters the Hartford city limits. In Hartford, I-91 it has a set of interchanges with US 5/Route 15 (Wilbur Cross Highway), which provides access from I-91 north to I-84 east, and from I-84 west to I-91 south via the Charter Oak Bridge.[15] I-91 then has an interchange with I-84, where all other movements to and from I-84 take place. Before leaving the city limits, an HOV lane begins that has its own set of interchanges up to exit 38.[16]

I-91 then enters Windsor, where it meets the western end of its other Connecticut spur route, I-291. At the Windsor–Windsor Locks town line, it meets the eastern terminus of the Route 20 expressway, which provides direct access to Bradley International Airport.[9] A couple miles north, I-91 crosses the Connecticut River on the Dexter Coffin Bridge into East Windsor. After traveling through East Windsor and Enfield, it crosses the Massachusetts state line into Longmeadow at milepost 58.[10]

I-91 travels 55 miles (89 km) through the Pioneer Valley of western Massachusetts paralleling the Connecticut River.[17] I-91 serves as the major transportation corridor through three Massachusetts counties, linking the cities of Springfield, Northampton, and Greenfield.[17] The three cities serve as the control cities listed on guide and mileage signs, along with Brattleboro, Vermont beginning with the first northbound conventional mileage sign (63 miles (101 km)) in Longmeadow.[3]

In Springfield, I-91 has an interchange with I-291 at exit 8, a 5.44-mile-long (8.75 km) spur going eastbound connecting with the Massachusetts Turnpike, for travelers going either east to Boston or west to Albany, New York.[18][19] North of Springfield, I-91 briefly enters Chicopee itself where there is an interchange with the spur of I-391 at exit 12 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.[13]

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. Route 202, I-91 goes from three lanes to two lanes in each direction to the Vermont state line.[13] After a short exit-less stretch, I-91 enters Northampton, passing the Northampton Airport and an oxbow lake. The towns of Hadley and Amherst, home to the main campus of the University of Massachusetts Amherst, are accessible from I-91 exits in Northampton via Route 9.[13]

Continuing north, I-91 enters Hatfield, and where it begins a straight section—nearly six miles (9.7 km) without a bend in the road. Several exits provide access to US 5 and Route 10 in Hatfield and Whately before entering Deerfield.[20] I-91 has two exits in Greenfield. At exit 26, the southern end of its overlap with Route 2, there is a rest area and visitor information center for Franklin County.[21] At exit 27, also in Greenfield, is the northern end of its overlap with Route 2 where access to that road is provided via a directional T-interchange, and exit and entry ramps on the left side of southbound I-91. Exit 28 in Bernardston is the last exit in Massachusetts. Beyond exit 28, I-91 continues for about five miles (8.0 km) more before crossing into Vermont.[3]

Massachusetts is the only state traversed by I-91 where another numbered highway is concurrent with the Interstate (in this case, US 5, for a one-half mile (800 m) spur near the Springfield-Longmeadow town line and Route 2, for approximately three miles (4.8 km) in Greenfield).[22]

I-91 travels along the eastern border of Vermont and serves as a major transportation corridor for eastern 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, as the points of access). The length of I-91 within Vermont is 177 miles (285 km) and has two lanes in each direction the entire way from the Massachusetts state line at Guilford to Derby Line at the Canadian border (nearly two-thirds of I-91's length) with 29 Vermont interchanges. The highway's rural character and long distances between exits in Vermont are in stark contrast to its south, where exits are more frequent and the road carries four lanes of traffic in each direction at some points. The major control cities in Vermont are Brattleboro, White River Junction, St. Johnsbury, and Newport. When re-entering northbound I-91 at exit 28 in Derby, the control city sign is for Canada. Of these destinations, only Newport is a city, although the other towns are sizable. In general, the road parallels its predecessor, US 5.[23][24][25]

I-91 enters Vermont in the town of Guilford. Just before exit 1 in Brattleboro is the Vermont Welcome Center in Guilford. The first three Vermont exits (northbound) serve the town of Brattleboro. At exit 1, northbound Route 5 provides access to stores and a small industrial area before reaching the south end of the town's center, where a bridge crosses the Connecticut River into Hinsdale, New Hampshire via NH 119. Exit 2 (VT 9) provides access to the western village of the town (West Brattleboro), then continues west to Marlboro, Wilmington, and Bennington. Brattleboro's main retail strip is located at and just south of the exit 3 trumpet interchange and traffic circle. Following VT 9 eastward, one can reach Keene, New Hampshire in 15 miles (24 km).[26][27]

After exit 3, I-91 heads north to travel through the towns of Dummerston, Putney, Westminster, Rockingham, Springfield, Weathersfield, Windsor, Hartland, and Hartford, home of the village of White River Junction. White River Junction, listed as a control city on mileage signs as far south as Greenfield, Massachusetts, is where I-91 and I-89 meet and provide access to many points in Vermont and New Hampshire, at exit 10.[28]

North of the interchange with I-89, I-91 continues towards St. Johnsbury and travels through the towns of Norwich, Thetford, Fairlee, Bradford, Newbury (with access to the village of Wells River), Ryegate, Barnet, and Waterford, 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 I-93, a major interstate highway in New England, which provides a direct route south 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 US 2. Along westbound US 2, the capital of Vermont, Montpelier, is eventually reached from I-91, although I-89 provides Montpelier with immediate Interstate access.[29][30]

I-91 continues northward, now following the Passumpsic River valley. It travels through Vermont's Northeast Kingdom region and the town of Lyndon. Two exits in Lyndon serve the village of Lyndonville and Lyndon State College. After exit 24, I-91 departs Route 5, which it had been closely paralleling since the Massachusetts state line. I-91 follows the valley of Miller Run,[31][lower-alpha 1] and there are no convenient services until Barton at exit 25.[32]

The interstate proceeds through Sheffield. Here it reaches the highest point on the road, just north of mile marker 150 on Sheffield Heights, elevation 1,856 feet (566 m).[33]

After leaving the Heights, it enters Orleans County and follows the Barton River valley north with exits in Barton, Orleans, and Derby. Exit 29 is the final U.S. exit on I-91 just after mile marker 177 at Derby Line. Beyond the exit ramp, northbound motorists enter Canada Customs at Stanstead, Quebec, and continue into Canada on Autoroute 55 through the Eastern Townships.[34][27]

As with Connecticut and Massachusetts, US 5 closely parallels I-91 for their entire lengths in Vermont. While paralleling I-91 in Vermont, US 5 is never concurrent with the freeway, but remains its own two-lane road, except for a portion in White River Junction where it is a four-lane divided surface arterial.[35][36]

Traffic and the population of each successive town tend to diminish as the road proceeds northward. The average daily traffic count for 2015 in Vermont were—St. Johnsbury (34,000), Lyndon (17,900), Barton (13,500), and Derby (Canadian border) (10,300).[37]