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.
Plans for 2021 or beyond call for improving the I-90/495 interchange. 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 or other high speed ramps to eliminate some of the weaving traffic patterns currently in place.
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.
Source: December 31, 2021 Interstate Route Log and Finders List
I-495 Annual Average Daily Traffic (AADT)
Source: 2016/17 MassDOT Transportation Data Management System
Interstate 495 was built in segments between 1958 and 1982.1 The route ended at Interstate 95 in Foxborough from the north until June 17, 1975, when the American Association of State Highway and Transportation Officials (AASHTO) approved the southeasterly extension to Interstate 195 at Wareham. This extension was previously approved by the Federal Highway Administration (FHWA) on May 23, 1974.
With mileage gained from the cancellations of both I-95 along the Southwest and Northeast Expressways through Boston, and the Inner Belt Expressway for I-695, the I-495 extension was added to the Interstate Highway System under the provisions of 23 U.S.C. 139(a) and 23 U.S.C. 139(e)(2). 14.2 miles of new construction lengthened I-495 southeast from Foxborough to the junction of Route 24/25 at Raynham. I-495 superseded an 18.5 mile long section of Route 25 from Raynham southeast to Middleborough and I-195 in Wareham. Interchanges were renumbered to start at Wareham instead of Foxborough.1
North End – Salisbury, Massachusetts
Continuing south from the wye interchange (Exit 60) with the connector to MSR 286 and U.S. 1 in Salisbury, I-95 proceeds one half mile to Interstate 495. I-495 loops southwest 11 miles to Haverhill while I-95 advances south to the John Greenleaf Whittier Bridge across the Merrimack River. Photo by H.B. Elkins (06/01/13).
South End – Wareham, Massachusetts