Interstate 91 runs 290 miles from New Haven, Connecticut to Derby Line, Vermont at the Canadian border, following the Connecticut River valley north through Hartford, Springfield (MA), and into the Green Mountains of Vermont. It is the principal north-south interstate of central New England.
For freight, I-91 is a main freight route for Connecticut and Massachusetts manufacturers and for Vermont dairy and timber industries. The Hartford-Springfield segment is heavily congested, and the Vermont segment has limited shoulders and frequent winter closures.
Geographically I-91 follows the broad Connecticut River valley for most of its length, with modest climbs through the Massachusetts Berkshires and the Green Mountains in Vermont. Weather hazards are dominated by lake-effect snow off Lake Champlain (in the northern Vermont segment), severe winter storms in the Green Mountains, and chronic congestion through the Hartford-Springfield corridor.
- Crosses three states: CT, MA, VT
- Follows the Connecticut River valley
- Northern terminus at the Derby Line border crossing into Quebec
- Concurrent with I-95 briefly at New Haven
- Toll-free across its entire 290-mile length
- Crosses the Vermont Green Mountains
- Hartford-Springfield segment is among the most congested in central New England