About the Route 27 over Route 9 interchange improvements, Natick

This project will replace the Route 27 bridge over Route 9 in Natick and reconfigure the interchange to increase safety, improve mobility and ease congestion.

Table of Contents


  • Replacing the existing Route 27 bridge over Route 9 with three independent bridge structures:
    • One bridge for Route 27 northbound vehicular traffic
    • One bridge for Route 27 southbound vehicular traffic
    • One bridge to accommodate a shared use path facility
  • Replacing the existing partial clover leaf interchange with a modified diverging diamond configuration.
  • Four transit stops (two along Route 9 and two along Route 27) with corresponding bus shelters for the MetroWest Regional Transit Authority (MWRTA).
  • Providing a shared-use path along the south side of Route 9 that will connect the Route 27 interchange area with the Cochituate Rail Trail (at the westerly project limit) and the MathWorks campus (at the easterly project limit).
  • Providing a new sidewalk along the north side of Route 9 within the project limits.
  • From Bacon Street to Rutledge Road, the project will provide a continuous shared use path along one side of Route 27 and a sidewalk along the other side.
  • Providing pedestrian-actuated warning systems at multiple crosswalk locations to increase driver awareness and yielding of crossing activity.
  • Providing two new traffic signals along Route 27 to accommodate the Route 27 crossing traffic (associated with the function of the modified diverging diamond).
  • Reconfiguring and improving access between Lakeshore Road and Route 27.
  • Reconfiguring the traffic signal at Route 27 at the 9/27 Exchange Driveway.
  • Reconfiguring the Route 9 on/off ramps to provide increased deceleration and acceleration lengths.
  • Upgrading and/or replacing existing drainage infrastructure along both Route 27 and Route 9 within the project limits.
  • Replacing the existing median barrier along Route 9.
  • Other ancillary items including low maintenance landscaping, stormwater improvements, retaining walls, guardrail, pedestrian fencing, new signage and new pavement markings.

This project is being considered for the Design-Build Project delivery method where one team handles both the design and construction. This reduces the time needed to complete the project and promotes collaboration among the engineers, contractor, and MassDOT staff.

Next Steps

  • Completion of 25% design plan review
  • Coordination with adjacent projects currently under construction
  • Coordination with impacted utility companies
  • Permitting
  • Design Public Hearing
  • Right-of-Way process
  • Prepare Design-Build procurement documents

Contact   for About the Route 27 over Route 9 interchange improvements, Natick

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