| Interstate Highways in Massachusetts | |
|---|---|
  Highway marker for I-90 and I-495 | |
 Interstate Highways highlighted in red | |
| System information | |
| Maintained by MassDOT | |
| Length | 565.63 mi[2] (910.29 km) |
| Formed | August 14, 1957[1] |
| Highway names | |
| Interstates | Interstate nn (I-nn) |
| System links | |
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).[3] 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.[4]
- ^ Public Roads Administration (August 14, 1957). Official Route Numbering for the National System of Interstate and Defense Highways as Adopted by the American Association of State Highway Officials August 14, 1957 (Map). Scale not given. Washington, DC: Public Roads Administration. Retrieved November 22, 2010 – via Wikimedia Commons.
- ^ Adderly, Kevin (January 15, 2014). "Table 3: Interstate Routes in Each of the 50 States, District of Columbia, and Puerto Rico". Route Log and Finder List. Federal Highway Administration. Retrieved May 20, 2014.
- ^ McDonald, Danny (December 5, 2022). "Transformative decision a half-century ago to scrap I-95 extension still resonates in Boston today". The Boston Globe. Archived from the original on December 5, 2022. Retrieved December 5, 2022.
- ^ "The Big Dig: tunnels and bridges". Massachusetts Department of Transportation. Retrieved December 5, 2022.