Interstate 495 Massachusetts
Interstate 495 is the outer beltway serving Boston metropolitan area commuters. Cities directly served by I-495 include Lowell, Lawrence and Haverhill. The highway also provides part of a bypass route from the Mass Pike south to Cape Cod and north to the New Hampshire Seacoast.
I-495 was the longest three-digit Interstate highway until 1996, when I-476 in Pennsylvania was extended north from Plymouth Meeting to Clarks Summit.
Interstate 495 north at the trumpet interchange and access road to the Mass Pike at Westborough. 10/06/14
I-495/I-90 Interchange Improvements
A five year project upgrades the interchange joining I-90/495 at the towns of Hopkinton and Westborough. With the Mass Pike switch to all electronic tolling (AET) on October 28, 2016, the toll plaza between the two trumpet interchanges linking the beltway and toll road was no longer needed. The removal of the toll barrier allows for the addition of flyovers and other high speed ramps to eliminate some of the weaving traffic patterns currently in place. Previously though to begin as early as 2021, the Massachusetts Department of Transportation (massDOT) provided an update on the design-build project on November 3, 2022.2
Commencing in May 2022, design work for the new exchnage runs through December 2024. Preliminary work got underway in October 2022. Work also expands I-495 northbound by a fourth lane between the Mass Pike and Route 9,2 and replaces the Fruit Street bridge over the beltway.
Referred by the Massachusetts Department of Public Works as the outer circumferential highway in a letter sent to the American Association of State Highway Officials (AASHO) on April 10, 1958, the number selected for the beltway around Boston was Route 95W. The letter W was selected to indicate that the route lies west of Interstate 95. This eventually changed to Route 495, and on November 13, 1958, AASHO approved it as part of the Interstate Urban Numerology for Massachusetts. I-495 was outlined along a route north from I-95 along the Mansfield/Foxboro town line to I-95 at Salisbury.