# List of Interstate Highways in Massachusetts

The Interstate Highways in Massachusetts comprise five current primary Interstate Highways and eight auxiliary Interstates. In addition, two auxiliary Interstates were proposed and then cancelled.
The longest Interstate Highway in Massachusetts is I-90 with 136 miles, followed by I-495 with 121 miles.
Several freeway projects in the Boston area planned as part of the Interstate Highway System were cancelled in the 1970s following community opposition, including the Inner Belt (I-695) and Southwest Expressway (I-95). The Big Dig megaproject in the 1990s and 2000s, which realigned several highways in Downtown Boston, included a new tunnel for I-93 to replace the Central Artery and an extension of I-90 via the Ted Williams Tunnel.

## Primary Interstate Highways

| Number | Length (mi) | Length (km) | Southern or western terminus | Northern or eastern terminus | Formed | Removed | Notes |
| I-84 | 8.15 | 13.12 | I-84 at Union, CT | I-90 in Sturbridge | 01958-01-011958 | 01971-01-011971 | Replaced part of former Route 15; Replaced by I-86 |
| I-84 | 8.15 | 13.12 | I-84 at Union, CT | I-90 in Sturbridge | 01984-01-011984 | current | Renumbered back from I-86 |
| I-86 | 8.15 | 13.12 | I-84 at Union, CT | I-90 in Sturbridge | 01971-01-011971 | 01984-01-011984 | Replaced I-84; was later reverted back to I-84 |
| I-89 | — | — | — | — | 01956-01-011956 | 01960-01-011960 | Proposed to replace US 7 in original 1956 plan; rerouted prior to construction |
| I-90 | 135.72 | 218.42 | I-90 at Canaan, NY | Route 1A in Boston | 01958-01-011958 | current | Follows the Massachusetts Turnpike |
| I-91 | 54.99 | 88.50 | I-91 at Enfield, CT | I-91 at Brattleboro, VT | 01958-01-011958 | current | |
| I-93 | 47.07 | 75.75 | I-95/US 1/Route 128 in Canton | I-93 at Salem, NH | 01957-01-011957 | current | |
| I-95 | 91.95 | 147.98 | I-95 at Pawtucket, RI | I-95 at Seabrook, NH | 01957-01-011957 | current | |
| I-95E | 40.73 | 65.55 | I-95E at E.Providence, RI | — | 01957-01-011957 | 01959-01-011959 | Replaced by I-195 |
| Former ||||||||

## Auxiliary Interstate Highways

| Number | Length (mi) | Length (km) | Southern or western terminus | Northern or eastern terminus | Formed | Removed | Notes |
| I-190 | 19.26 | 31.00 | I-290 in Worcester | Route 2 in Leominster | 01983-01-011983 | current | |
| I-195 | 40.73 | 65.55 | I-195 at E.Providence, RI | I-495 at Wareham | 01959-01-011959 | current | Replaced I-95E |
| I-290 | 20.16 | 32.44 | I-395/I-90 in Auburn | I-495 in Marlborough | 01970-01-011970 | current | |
| I-291 | 5.44 | 8.75 | I-91/US 20 in Springfield | I-90 in Chicopee | 01972-01-011972 | current | also known as the Springfield Expressway |
| I-295 | 4.23 | 6.81 | I-295 at Cumberland, RI | I-95 in Attleborough | 01969-01-011969 | current | |
| I-391 | 4.46 | 7.18 | I-91 in Chicopee | High Street in Holyoke | 01970-01-011970 | current | |
| I-395 | 11.91 | 19.17 | I-395 at Thompson, CT | I-290 in Auburn | 01983-01-011983 | current | |
| I-495 | 121.56 | 195.63 | Route 25 in Wareham | I-95 in Salisbury | 01960-01-011960 | current | Second longest auxiliary Interstate highway in the United States |
| I-495 BS | 2.88 | 4.63 | US 3 in Chelmsford | Gorham Street in Lowell | 01962-01-011962 | current | Unsigned; known as Lowell Connector; signs were posted at one time on local streets intersecting the Connector |
| I-695 | — | — | I-95 in Boston | I-93 in Charlestown | 01957-01-011957 | 01971-01-011971 | Cancelled before it was constructed |
| I-895 | — | — | I-895 at Warren, RI | I-95 and I-295 in Attleboro | 01968-01-011968 | 01982-01-011982 | Cancelled before it was constructed |
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