• CDD >
  • Projects >
  • Allston I-90 Interchange Improvement Project

Allston I-90 Interchange Improvement Project

The I-90 Allston Interchange Improvement Project is being conducted by MassDOT and results from the need to replace the structurally deficient, functionally obsolete Allston Viaduct. This also offers the opportunity opportunity to dramatically reduce the footprint of the existing Allston Interchange toll plaza and along with Harvard University, the property owner, create a new neighborhood in Allston. In planning for new turnpike access, the project is looking all transportation facilities and connections including a new roadway system, as well as bicycle and pedestrian facilities and the creation of a new stop on the Worcester/Framingham Commuter Line to be known as West Station. Since 2014, MassDOT and its design team have worked with a task force composed of local residents, advocates, representatives of local institutions and businesses, and officials both elected and appointed, to develop a concept for the replacement of the Allston Interchange which includes:

  • Complete streets improvements to Cambridge Street.
  • Enhanced bicycle and pedestrian connectivity among the different parts of Allston touched by the project area and the Charles River.
  • A significant transit enhancement in the form of West Station and Commuter Rail Layover which will provide access and operational improvements to the commuter rail and an intermodal focal point for local bus service.
  • A realigned I-90 mainline, straightened to take full advantage of the safety enhancements made possible by AET.
  • A replaced I-90 Allston Viaduct to ensure that this section of a critical regional highway can continue to safely and efficiently carry traffic to and from Boston.
  • Connecting roadways between Cambridge Street and I-90 built, to the fullest extent practical and safe, on complete streets principles to clearly signal to motorists leaving the highway that they are entering a community.

Cambridge is involved with the task force team which meets regularly and includes two members from Cambridge - a resident and a Community Development staff person. The City of Cambridge representatives are focused on many aspects of the project including providing enhanced connectivity through the site to the Charles River and across to Cambridge for all modes, as well as project noise, urban design/green space and improved transit connections to Cambridge.

Draft Environmental Impact Comments

On February 9, 2018 the City of Cambridge submitted its comments on MassDOT's Draft Environmental Impact Report for the Allston I-90 project. The city's comments may be found here. After review of all comments submitted, the state's MEPA office released a certificate with conditions for the project to address. The certificate may be found here. Cambridge will continue to be involved with this process while MassDOT develops a final proposed design. In the fall of 2019 a Final Environmental Impact Report is expected to be released and there will be an additional period for public comments.  

Public Meeting Scheduled for January 3, 2018

A meeting will be held to provide the public with an introductory overview to the Draft Environmental Impact Report (DEIR) for the Allston I-90 Interchange Project. It will provide attendees with guidance on how to comment on the document. In case of inclement weather on the 3rd, this meeting will be held on January 10, 2018.

When: January 3, 2018, 6:30 P.M. to 8:30 P.M.

Where: Morse School, 40 Granite Street, Cambridge 

For more information, please see the project webpage. 

Project documentation can be found on the Mass Department of Transportation project webpage.

The elevated viaduct carries the Massachusetts Turnpike (I-90) through the Allston/Brighton area with Cambridge Street and Soldiers Field Road to the north and Brighton Avenue to the south. This section of the Massachusetts Turnpike has an Average Daily Traffic volume of approximate 144,000 vehicles per day. The viaduct is the primary East-West route between Western Massachusetts, Worcester and Boston, and experiences extensive vacation traffic during the weekends in the summer and winter. Average daily traffic volumes for the Massachusetts Turn pike west of the Allston Interchange are 142,000 and east of the Allston interchange are 147,000. Average daily traffic volumes for Cambridge Street are 38,000, Soldiers Field Road are 66,000 and the Allston Interchange Ramps are 66,000.

The I-90 Allston viaduct is nearing the end of its useful lifespan and must be replaced to prevent the bridge from becoming structurally deficient. The replacement of the bridge provides an opportunity to reconfigure the Allston Interchange which dates to the 1965 extension of the Massachusetts Turnpike to downtown Boston. This project is in alignment with MassDOT's plan to convert the Massachusetts Turnpike to all electronic tolling which will operate at highway speeds.

For additional information, or to be added to future informational mailing lists, please contact:

Nathaniel Curtis, Howard/Stein-Hudson, Public Involvement Specialist


(617) 482-7080 x236