Interstate 89 was originally planned to follow an entirely different path through New England

Science · Published 20 October 2026 Swipe more like this →

In short: Commissioned in 1956 to link Connecticut to the Canadian border, Interstate 89 was meant to follow the US 7 corridor. However, local opposition and concerns about cutting through the Green Mountain National Forest forced a massive realignment, ultimately creating the vital Boston-to-Montreal artery we know today.

The original vision for I-89, established by the Federal-Aid Highway Act of 1956, aimed to connect Norwalk, Connecticut, to the Canadian border via a direct north-south route. This plan faced significant resistance from interior New England residents and lawmakers who feared the impact of a major interstate on their rural landscapes. A primary obstacle was the proposed path through Vermont's Green Mountain National Forest. While small segments of this original design were built in Connecticut and southern Vermont, the project was largely abandoned in favor of the current alignment that connects Boston and Montreal.

The modern I-89 route, which spans about 61 miles in New Hampshire and continues through Vermont to Highgate Springs, was finalized after Massachusetts lobbied for a more effective freeway connection between Boston and Montreal. Construction began in 1960, with the first sections opening between Montpelier and Middlesex in November of that year. The entire route was not fully opened until 1982. Today, it remains a critical corridor, serving as the only interstate to directly connect Vermont's capital, Montpelier, and its largest city, Burlington.

The highway's history is marked by unique engineering and administrative quirks. For years, a section between exits 9 and 10 in Vermont featured the only solely metric distance signs in the entire US Interstate System, until they were replaced in 2010. Furthermore, the highway contains unusual exits like those in Enfield, New Hampshire, named 'Montcalm' and 'Purmort'—names chosen in 1960 to honor local history, despite the settlements not existing at the time of construction. Today, the focus has shifted to modernization, including the construction of Vermont's first diverging diamond interchange at exit 16, expected to be completed by mid-2026.

While I-89 is a major artery, it remains technically incomplete. The planned connection to Montreal relies on Autoroute 35 in Quebec, which has faced significant delays, with final phases indefinitely postponed as of March 2025. Despite this, the route remains a vital piece of infrastructure, navigating the challenging terrain of the Green Mountains and providing essential access to the region's population centers.

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