US 3 / Northwest Expressway¹

19 Miles, From I-95/128 in Burlington to NH Border

Exits Renumbered between January 20 and February 10, 2021

(Updated 3/6/24 based on new signage being installed in 2024)

Interchange	Milepost	New Exit Number	Old Exit Number
() South - Providence, RI (SB)	72.0	72A**	25A
() North - Portsmouth, NH (SB)	72.0	72B**	25B
- Burlington, Bedford	72.9	73	26
Concord Rd - Billerica, Bedford	76.1	76	27
Treble Cove Rd - N. Billerica	77.5	78	28
- Billerica, Chelmsford	79.7	79 (80)*	29
Lowell Connector (NB)	81.2	80 (81A)*	30B
North - Lawrence	81.2	81A (81B)*	30A
South - Marlboro	81.2	81B (81C)*	30C (30B SB)
-  Lowell, Chelmsford	81.5	81C (82)*	31
- N. Chelmsford, Chelmsford	83.7	84	32
- Westford, N. Chelmsford	85.8	86	33
Westford Rd - Tyngsboro	88.0	88	34
- Dunstable, Tyngsboro	89.6	90	35
Middlesex Rd - Tyngsboro  Daniel Webster Hwy -  S. Nashua, NH (NB)	91.0	91	36

This exit list contains both the new exit number and former sequential exit number when MassDOT converted US 3 to the Geographic Reference or Milepost Exit Numbering system in January and February 2021. MassDOT started to convert exit numbers in late October 2020 with routes in the southeastern part of the state. This project was first planned for 2016, but eventually postponed. US 3's mileage is a continuation of the mileage of MA 3 from it's beginning at MA 2A in Cambridge.¹

Sign poles and gantries awaiting installation along US 3 North near the Westford Road exit in August 2023, courtesy of Kevin Manfra:

 

Check out photos of new 2024 exit signs along US 3 at Misc. Mass. Sign Photos.

*Numbers in ( ) listed for the postponed 2016 Renumbering Project.

**MassDOT originally proposed numbers for the SB I-95 exits as 70A and 70B. Due to comments sent to MassDOT by myself and others that the exit was closest to mile marker 72, the exit number was changed to 72 A/B on a subsequent US 3 revised exit list.

1. I sent comments to MassDOT suggesting that since US and MA 3 are treated as the same road why not sign the highway from NH to Cape Cod simply as US 3, and, perhaps, like US 1, it could all be moved off of local streets in the Boston area. This was the answer I received:

"The MA Route 3 designation cannot be changed to US 3 because Route 3 between the Mass. Ave Bridge and I-93 at Leverett Circle does not meet current AASHTO design standards, particularly regarding minimum vertical bridge clearances, to be given a US Route designation.  Rerouting US 3 between Burlington and Boston via I-95 (128) and I-93, which would require AASHTO review and approval before implementation, is not considered a practical option at this time.  This is due to capacity constraints at the I-95/I-93 interchange in Woburn, and would also require an outreach effort and highway sign changes that are beyond the scope of this project."

I also suggested that, as an alternative to the above, since most drivers think of Routes 3 north and south of Boston as 2 routes, perhaps they could be simply split into 2 routes with the designation removed between Burlington and Braintree, the response:

"As you note, media traffic reporters, the general public, and others generally consider Route 3 to be two separate roads, one from Braintree south and the other from Burlington north.  Also, the freeway segments of US 3 and MA 3 already have distinct sets of exit numbers that do not duplicate – this will still be the case after milepost numbering is implemented.  For these reasons, and given the additional outreach effort and changes to highway signs required – both of which are outside the scope of this project, MassDOT sees little tangible benefit to the public to justify removing the Route 3 designation between Braintree and Burlington entirely."

• Return to Interstate and US Highway Exit Lists

© Robert H. Malme 2014-2024