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

The Allston Viaduct carries the Massachusetts Turnpike (I-90) from the Allston Interchange to the Commonwealth Avenue Bridge. Its replacement is necessary as it reaches the end of its useful lifespan.

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.


  • September 2021: MassDOT has identified the Modified At-Grade Option as the agency’s path forward. The NPC will reflect this change. Permitting, logistical, and financing challenges remain for the option, but MassDOT is committed to addressing them.
  • Fall 2021 – Fall 2022: The project team is also working towards filing a joint document with the Final Environmental Impact Report (FEIR) and Draft Environmental Impact Statement (DEIS).
  • Fall 2021- Winter 2021: MassDOT and its Design Team are working to file a Notice of Project Change (NPC) to reflect the recent changes to the project and bring the State and Federal processes into alignment.
  • Summer 2021: MassDOT began advancing Phase One of the Allston Multimodal Project. It will address 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.
  • November 2020: Secretary Pollock announced the identification of a preferred throat option will happen after the next round of environmental filings and the No Build Major Preservation Alternative remains to allow time to build consensus on the throat area option and determine a finance plan for the project. Construction of the No Build option would also allow MassDOT to get through a lengthy permitting process should MassDOT pursue a build alternative at a later date.
  • October 2020: 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 Scoping Summary Report, one based on extensive discussions with the City of Boston.
  • 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.
  • 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 collected 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: 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)

Project timeline

  • Concept development-through end of 2021
  • Public outreach-ongoing throughout project duration
  • MEPA/NEPA/Permit filings- First quarter 2021- through fourth quarter 2022
  • Preliminary Design- all of 2022-
  • Design-Build procurement- Fourth quarter 2022 through third quarter-2023 –
  • Construction- Fourth quarter 2023-early 2024 - construction begins, lasting 6 to 10 years depending on the throat option selected.
A timeline of the project from concept development to the end of construction. It is currently anticipated that construction will begin in 2022 and continue for eight to 10 years.

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
  • Specific Benefits of the Modified At-Grade Option:
    • Removing elevated bridge structure allows for an improved gateway into the city and enhanced neighborhood views.
    • Incorporating a boardwalk in the Charles River improves views and creates more separation between Paul Dudley White Path users and Soldiers Field Road.
    • Allows for an attractive and highly desired pedestrian/bicycle connection from Agganis Way to Charles River.

Environmental Documentation Preview

Originally developed in 2018 as compromise between a new highway viaduct and an all at-grade concept, the Soldiers Field Road Hybrid would have put Soldiers Field Road on a small viaduct over a grounded I-90. Originally favored, over the course of 2019 and 2020, public opinion turned against the hybrid due to the need for a temporary trestle in the Charles River during 8-10 years of construction, a timeframe many commenters identified as too long. The shift in opinion became clear in the public comments received and made public in the August 2020 Scoping Summary Report. Based on the feedback received, the project team:

  • Implemented a Major Preservation/No Build option for the viaduct
  • Identified 3L Realignment Alternative as the Build Alternative for the interchange
  • Revised the Modified At-Grade and Modified Highway Viaduct options to:
    • Be able to accommodate a potential future north-south pedestrian/ bike connection from Agganis Way to the Paul Dudley White Bicycle Path
    • Address visual impacts with aesthetic treatments
  • Revised West Station and layover yard rail design to include 4 tracks and 3 platforms

As of September 2021, the Modified At-Grade option, based on the comments received on the Scoping Summary Report, was chosen as the agency’s path forward. The Modified At-Grade, SFR Hybrid, and Modified Highway Viaduct will all undergo the applicable environmental analysis and permitting process required by NEPA, but the At-Grade Option will be the area of focus. Permitting, logistical, and financing challenges remain for the Modified At-Grade, but MassDOT is committed to addressing them.



Dan Fielding, Legislative Liaison - MassDOT Highway Division (857) 368-8959


Email the Project Team I-90Allston@dot.state.ma.us


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