Northwest Expressway (Massachusetts)
|Maintained by MassDOT|
|Length:||19.3 mi (31.1 km)|
|South end:||I‑95 / Route 128 / US 3 in Burlington|
|Lowell Connector in Chelmsford
I‑495 in Chelmsford
|North end:||US 3 / Everett Turnpike near South Nashua, NH|
The Northwest Expressway is a 19.3-mile expressway that carries U.S. Route 3 from its junction with Interstate 95 (Route 128) in Burlington north to the New Hampshire state line in Tyngsborough, where it connects to the Frederick E. Everett Turnpike.
The expressway serves as a freeway connection between the metro Boston area and the Everett Turnpike in Nashua (which provides further connections north and east of Nashua), bypassing downtown areas along US-3's former alignment, now designated as the northern stretch of Massachusetts Route 3A. Aside from this connection, an important interchange rests in Chelmsford, where US-3 intersects with Interstate 495. This interchange is also located at the southern terminus of the Lowell Connector, a short freeway spur into the nearby city of Lowell.
U.S. Route 3 breaks off from its surface alignment in Burlington, at the Exit 33 interchange with I-95/Route 128. Route 3A continues the old alignment from this point north to the border, while US-3 joins I-95 and Route 128 in a wrong-way concurrency lasting approximately one mile. At Exit 32A, US-3 exits from I-95 onto the Northwest Expressway.
The freeway heads in a generally northwest direction, with interchanges providing access to the nearby towns of Burlington, Bedford, Billerica, Carlisle, and Chelmsford. In Chelmsford, US-3 meets I-495, which provides northbound connections to Lawrence, Haverhill and points north and east, as well as southbound connections to Worcester and points west. This interchange also provides northbound-only access to the Lowell Connector which runs northeast into the city of Lowell. US-3 runs west of the Merrimack River, continuing north near the towns of North Chelmsford, Westford, Dunstable and Tyngsborough before reaching the New Hampshire state line.
Upon crossing into South Nashua, NH, the Everett Turnpike begins overlapped with US-3. The U.S. highway remains on the freeway for another 6.7 miles, before exiting onto its surface alignment.
The final section of the expressway was an unbuilt expressway, planned for inner suburban towns northwest of Boston, Massachusetts. The expressway was to supply a new route for U.S. Route 3, between MA 128 and the cancelled Interstate-695/Inner Belt. The highway was one of the expressway projects cancelled in the Gov. Francis Sargent's 1970 moratorium on expressway construction within MA 128. The latter section of the expressway was a key component of the "Master Plan Highway Plan for Metropolitan Boston."
The highway would have travelled through Lexington, Arlington, Medford, Somerville, and Cambridge, before linking with the Inner Belt Expressway.
The original plan called for U.S. 3 and MA 2 to link up together at the Lexington-Arlington border, and continue southeasterly, crossing MA 16/Mystic Valley Parkway at the Arlington-Somerville border and proceeding into Cambridge toward Union Square, Somerville. A 1962 plan called for Routes 2 and 3 to converge at Alewife Brook Parkway with a longer stretch of new highway for Route 3 paralleling Lowell Street in Lexington and Summer Street in Arlington.
- "Boston's Big Dig that never was" http://www.bettnet.com/bostons_big_dig_that_never_was/
- Lupo, Alan, Colcord, Frank, and Fowler, Edmund P. Rites of Way: The Politics of Transportation in Boston and the U.S. City. Boston: Little, Brown, 1971.