Interstate 93 (I-93): Boston to Vermont Route, Miles and Safety Data

How long is I-93?

In the January 2026 federal Route Log, I-93 measures 188.91 miles. New Hampshire has 131.65 of them, close to 70 percent of the road. Massachusetts has 46.16 miles and Vermont 11.10.

Most references print 189.95 miles, the figure on Wikipedia and Interstate Guide, with state rows of 47.07 in Massachusetts and 131.78 in New Hampshire. Interstate Guide credits its numbers to the December 31, 2021 edition of the Route Log. The federal rows for I-93 carry no shared-pavement notes, so the gap of about a mile looks like a later federal remeasurement, mostly on the Massachusetts end.

Where I-93 starts and ends

I-93 starts in Canton, Massachusetts, at its interchange with I-95, US 1 and Route 128 south of Boston. It ends at I-91 by St. Johnsbury, Vermont. Wikipedia's exit table puts that last interchange in Waterford, the next town over, so you will see both names.

Heading north, the road follows the Southeast Expressway into Boston, where US 1 and Route 3 share its lanes, then dives into the Thomas P. O'Neill Jr. Tunnel and climbs onto the Zakim Bunker Hill bridge over the Charles River. Past Medford it crosses into New Hampshire at Salem and runs through Manchester and Concord. North of Lincoln it threads Franconia Notch on a parkway shared with US 3, then passes Littleton before entering Vermont.

Interstate junctions along I-93

The list runs south to north. I-95 shows up twice, first at Canton, where I-93 begins, and again north of Boston; the I-95 guide lists both meetings from its side. I-90 meets it in Boston, and I-89 splits off at Bow, near Concord. After that, I-93 meets no other main Interstate until it reaches I-91 at its northern end.

Fatal crashes on I-93

Fatal crashes on I-93 killed 88 people from 2020 to 2024, or about 18 a year. Each year that comes to 9.3 deaths for every 100 miles of road, slightly below the 9.5 average for the whole Interstate network, and puts I-93 24th of the 56 Interstates long enough to rank.

The average hides a sharp split between the two main states. Massachusetts recorded 49 deaths on its 46.16 miles, a rate of 21.2, while New Hampshire's 131.65 miles had 39 deaths and a rate of 5.9. Vermont's 11.10 miles had none. Middlesex County, Massachusetts, led all counties with 20 deaths, followed by Grafton County, New Hampshire, with 13 and Suffolk County, Massachusetts, home to Boston, with 12. Merrimack County, New Hampshire, had 10 and Norfolk County, Massachusetts, 9. Deaths rose from 13 in 2020 to 23 in both 2021 and 2022, then fell to 14 in 2023 and 15 in 2024.

Counties with the most I-93 crash deaths

Bridges on I-93

The 2025 National Bridge Inventory counts 307 bridges carrying the I-93 main line. Their median year of construction is 1968. Only 5 rate Poor, about 1.6 percent, and all five are in Massachusetts. New Hampshire's 200 bridges and Vermont's 12 have none in Poor condition. Of the full set, 122 rate Good and 180 Fair.

In August 2010 part of a bridge deck on I-93 in Medford gave way. Massachusetts answered with the "93 Fast 14" project in summer 2011, which replaced bridges in Medford for $98.1 million, according to Wikipedia.

Tolls on I-93

As of January 2023, FHWA's toll inventory has one entry for I-93: the 10.05-mile F.E. Everett Turnpike segment that New Hampshire DOT runs. FHWA lists the facility from Exit 10 in Hooksett to Exit 12 in Concord; on the road, the turnpike stretch begins at the unnumbered I-293 split in Hooksett. A through driver pays once, at the Hooksett toll plaza. Through December 31, 2026, cars pay $1.00 cash at the main line plaza ($0.70 with NH E-ZPass) and $0.50 at the ramp ($0.35). Under HB 2026, from January 1, 2027, cash and non-New Hampshire E-ZPass drivers pay $2.00 on the main line and $1.00 at the ramp, while NH E-ZPass stays at $0.70 and $0.35.

The 10.05 miles is FHWA's length for the turnpike facility as a whole, not a distance drivers pay by. The Massachusetts and Vermont sections, the Big Dig tunnel included, have no tolls in the FHWA list.

I-93 auxiliary routes

I-93 has two three-digit spurs, both in New Hampshire. I-293 is an 11.77-mile loop on the west side of Manchester, and I-393 is a 4.59-mile spur east from Concord. Massachusetts and Vermont have no I-93 branches.

From the Central Artery to Franconia Notch

I-93 was designated on August 14, 1957. Boston's Southeast Expressway was built from 1954 to 1959, and the 24-mile Northern Expressway from Medford to the New Hampshire line opened in 1963 after seven years of work. Massachusetts asked in 1974 to move I-93 onto the elevated Central Artery through downtown. AASHTO approved the extension south to Braintree on June 17, 1975, and west along Route 128 to I-95 in Canton on November 15, 1975, which gave I-93 its current southern end.

In New Hampshire the first stretch built new for I-93 opened in Salem in August 1961, though the Everett Turnpike section from Hooksett to Concord that I-93 now uses dates to 1957. The road reached Plymouth by 1965, but gaps remained until 1977, 1984 and 1988. Vermont's 11 miles opened on October 29, 1982, after agricultural lawsuits held them up. The last piece was the Franconia Notch Parkway, dedicated on June 2, 1988. It runs about 9 miles, mostly with one lane in each direction and a 45 mph limit, a design chosen to limit damage to the notch.

The Big Dig replaced Boston's elevated artery with the O'Neill Tunnel, which carries 1.5 miles of I-93 between Kneeland and Causeway Streets. The northbound tunnel opened on March 29, 2003, and southbound followed on December 20, 2003. The project wrapped up in December 2007 at $14.6 billion, against an early estimate of $2.8 billion, and the Rose Kennedy Greenway now covers the ground where the old elevated road stood. On July 10, 2006, ceiling panels fell on a car in the ramp from northbound I-93 to eastbound I-90 and killed passenger Milena Del Valle. The NTSB found that the epoxy anchoring the ceiling could not hold long-term loads. Farther north, New Hampshire widened I-93 between Salem and Manchester from 2006 to 2021.

I-93 traffic and road conditions

For closures, crashes and roadwork on I-93 right now, check the state traveler sites below: Mass511 for the Massachusetts end and New England 511 for New Hampshire and Vermont.

I-93 questions