About the Allston Multimodal Project

The Allston Viaduct, which carries the Massachusetts Turnpike (I-90) from the Allston Interchange to the Commonwealth Avenue Bridge, is nearing the end of its useful lifespan, and must be replaced.

Table of Contents

Project background

The Allston Interchange carries the Massachusetts Turnpike (I-90) through the Allston/Brighton area. Cambridge Street and Soldiers’ Field Road are to the north and Brighton Avenue to the south. This is the primary east-west route between Western Massachusetts, Worcester, and Boston. It carries heavy vacation traffic during the weekends in the summer and winter.

Average daily traffic volumes for the Turnpike:

  • east of the Allston interchange are 150,000 average daily travel (ADT)
  • Cambridge Street carries 27,000 ADT
  • Soldiers’ Field Road carries 75,000 ADT
  • the Allston Interchange Ramps carry 75,000 ADT

With the change to All Electronic Tolling, toll booths have been removed from the interchange. This allows for the straightening of the Turnpike in Allston. It also allows for improvements to multimodal connections.

Since the spring of 2014, MassDOT and its Design Team have been developing a concept for the replacement of the Allston Interchange. The team is working with a Task Force composed of:

  • elected and appointed officials from Allston, MetroWest, and Central Massachusetts
  • representatives of local institutions
  • businesses
  • local residents
  • advocates
  • the Allston community at-large


  • southern limit – Ashford Street
  • northern limit – Cambridge Street
  • eastern limit - Boston University Bridge/Commonwealth Avenue
  • western limit - Cambridge Street and the Franklin Street pedestrian bridge over I-90
A map of the Boston area with the project area highlighted, and the Worcester/Framingham Commuter Rail Line labeled.

Project Benefits

The interchange is crucial to the Commonwealth's roadway network. Improvement to I-90 as part of this project will ensure its efficient operation. Improvements include:

  • Improved livability, connectivity, and open space for residents of the Allston neighborhood
  • Improved regional mobility and roadway safety with the straightening of I-90. The project will also shrink the Allston interchange.
  • Replacing the aging Allston Viaduct, decreasing the need for traffic-impacting maintenance on this section of I-90
  • Creating a new open space along the Charles River
  • Complete Streets improvements to Cambridge Street
  • Enhanced bicycle and pedestrian connections
  • Significant transit enhancements with the new West Station and Commuter Rail layover facility, providing greater access and improvements to the Commuter Rail and local bus service
  • Removing elevated bridge structure allows for an improved gateway into the city and enhanced neighborhood views.
  • Allows for an attractive and highly desired pedestrian/bicycle connection from Agganis Way to Charles River.

Project Milestones

August 2022 MassDOT and its Design Team file a Notice of Project Change to reflect the recent changes to the project and bring the State and Federal processes into alignment
September 2021 MassDOT identified the Modified At-Grade Option as the agency’s path forward in the Throat Area.
Summer 2021 MassDOT began advancing the Bridge Preservation Project. Its purpose is to address immediate concerns regarding the ongoing and accelerating deterioration of the existing viaduct. These repairs will ensure the structure remains in good condition and continues to carry roadway traffic safely. The Bridge Preservation Project does not affect the overall purpose of and need for the I-90 Allston Multimodal Project and does not limit the consideration of alternatives for the larger project.
November 2020 MassDOT announced the identification of a preferred throat option will happen after the next round of environmental filings.
October 2020 After extensive discussions with the City of Boston, MassDOT held an additional round of public engagement as MassDOT formally requested the substitution of a Modified At-Grade option in place of the at-grade throat option presented in the NEPA Scoping Summary Report.
August 2020

The NEPA Scoping Summary Report was filed. The Scoping Summary Report updated the design of the highway viaduct and at-grade throat area options – re-named the Modified Highway Viaduct and Modified At-Grade, respectively, and identified three throat area design options under the 3L Re-alignment Alternative would be moving forward to the DEIS for further analysis.

While the public had favored the Soldiers Field Road Hybrid in 2019 and 2020, comments on the Scoping Report showed less support for this throat option due to its potential impacts to the Charles River. Based on the public feedback received during scoping, the project team:

  • Updated the No Build Alternative to include major preservation of the viaduct
  • Identified 3L Realignment Alternative as the Build Alternative for the interchange
  • Revised the Modified At-Grade and Modified Highway Viaduct options to:
    • Accommodate a potential future north-south pedestrian/ bike connection from Agganis Way to the Paul Dudley White Bicycle Path
    • Review opportunities to address visual impacts of the Modified Highway Viaduct with aesthetic treatments
  • Revised West Station and layover yard rail design to include 4 tracks and 3 platforms
November 2019 The NEPA Scoping Report was published. The Scoping Report updated the design of the 3K interchange alternative, re-named the 3L Re-alignment Alternative, and presented three throat area options: the Highway Viaduct, At-Grade and SFR Hybrid designs. A 37-day comment period followed. It closed on December 12 and the project team received over 2000 individual substantive comments.
October 2019 Federal Highway Administration (FHWA) publishes Notice of Intent to prepare an Environmental Impact Statement in the Federal Register. This officially starts the federal National Environmental Policy Act (NEPA) environmental review of the project, to be processed as One Federal Decision (OFD) per Executive Order 13807.
Summer 2019 Project team conducted public outreach to MetroWest Communities, Boating Communities and Task Force to review construction impacts of the Soldiers Field Road Hybrid option.
January 2019 The Secretary of Transportation selected the Soldiers’ Field Road (SFR) Hybrid for further analysis in the throat. This concept would lower I-90 while raising Soldiers’ Field Road onto its own small viaduct.
Summer 2018 An Independent Review Team (IRT) analyzed options for the section of the project containing the Allston Viaduct, known as “the throat.”  
February 2018 EEA issued MassDOT a scope of work for a Final Environmental Impact Report (FEIR).  
November 2017 MassDOT submitted the Draft Environmental Impact Report (DEIR). It identified a preferred concept for the new interchange design – the 3K Alternative.  
2014 Current urban interchange defined in the Environmental Notification Form (ENF) submitted to the Executive Office of Energy and Environmental Affairs (EEA).  

Contact   for About the Allston Multimodal Project


Carrie E. Lavallee, PE, MassDOT, Chief Engineer
10 Park Plaza, Attn: Bridge Project Management – Project File No. 606475 , Boston, MA 02110

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