Interstate 89 is a scenic highway serving the states of Vermont and New Hampshire in northern New England. The freeway joins the capital cities of Montpelier and Concord as part of its northwestern route from outside Concord to Lebanon, Burlington and Lake Champlain. Continuing northward from Swanton, Interstate 89 transitions into Quebec Route 133, which leads north to Autoroute 35 (A-35).
A-35 (Forts Valley Highway) extends 25 miles south from A-10 and Chambly in the Montréal suburbs to Route 133 in Saint-Sébastien, Quebec. Proposed to link directly with Interstate 89 since the 1960s, construction finally broke ground on August 27, 2020 for the 8.9 kilometer (5.6 miles) section between Saint-Sébastien and Saint-Armand. Costing $222 million, phase III of A-35 takes the freeway southeast to Route 133 at Champlain and du Moulin in Saint-Armand, where an interchange will be built. Slated to start in 2023, Phase IV builds the final 4.5 kilometers (2.8 miles) of the highway south to the U.S. border at Highgate, Vermont. The Quebec Ministry of Transportation (MTQ) anticipates full completion of construction in 2025.5,6
Phases I and II previously extended A-35 south from Route 133 at Saint-Jean-sur-Richelieu to Route 133 west of Pike River. Completed in 2014, the projects totaled around $200 million in costs.7
The Vermont Agency of Transportation (VTrans) added supplemental signs displaying the milepoint to exit signs along Interstate 89 and other limited access highways statewide by the end of Spring 2020. The addition aimed to defer a Federal Highway Administration (FHWA) requirement made in 2009 that all exit numbers use a mileage based system. Vermont still uses sequential exit numbering, and the addition of milepoint exit placards allows the existing signs to remain in place to the end of their service life.8
Interstate 89 follows an independent alignment northwest from Concord to Lebanon, where U.S. 4 ties in from Enfield to the east. U.S. 4 parallels I-89 for 11 miles to White River Junction and Hartford in Vermont. Northwest from there, I-89 replaced VT 14 as the main route to Barre and Montpelier.
U.S. 2 accompanies the freeway west from Montpelier to South Burlington, shifting sides with I-89 several times. U.S. 7 combines with U.S. 2 north from Burlington to Colchester. U.S. 2 turns west through the Lake Champlain Islands while U.S. 7 remains along the I-89 corridor to the Canadian border at Highgate.
Interstate 89 opened initially in New Hampshire between Warner and New London in November 1967. Completion within the state followed a year later.`
Within Vermont, Interstate 89 was built in stages through the 1960s:1
- Montpelier to Middlesex (6.287 miles) – November 21, 1960
- Middlesex to Waterbury (5.106 miles) – December 31, 1960
- Waterbury to Bolton (7.049 miles) – November 20, 1961
- South Burlington to Winooski (3.388 miles) – November 29, 1962
- Winooski to Colchester (1.184 miles) – November 1, 1963
- Richmond to South Burlington (8.723 miles) – November 6, 1963
- Bolton to Richmond (6.745 miles) – October 30, 1964
- Colchester (6.486 miles) – November 1964
- Swanton to Highgate (5.538 miles) – 1965
Interstate 89 between White River Junction and Montpelier, Vermont – 1966 Vermont Official Highway Map.
The last stretch of Interstate 89 constructed ran south from Memorial Drive at Montpelier to the temporary end at VT 14 by West Hartford.