We are halfway through the two-year, $157 million restoration of the Sumner Tunnel. While the full two-month summer closure has ended, there are more weekend closures this fall, and another two-month summer shutdown planned for 2024.

The 90-year-old tunnel, which spans one mile under Boston Harbor, was the first traffic tunnel built in Massachusetts. Today, it carries 40,000 vehicles daily. The condition of the tunnel worsened to such a state in recent years that Massachusetts Department of Transportation officials decided repairs were not enough to keep up with the pace of deterioration — the tunnel needed a top-to-bottom restoration.

The full closure for this extensive project was originally scheduled for seven months, but accelerated construction techniques and working 24/7 within the tunnel allowed MassDOT to shorten that timeline. To further mitigate the impact, the job was broken up into segments during the summer and on weekends when traffic is at its lowest volume.

During the first full two-month closure this past summer, the overhead concrete arch and ceiling was replaced, the walls were repainted and new ventilation, drainage, fire suppression systems and lighting were installed.

In July and August 2024, workers will rebuild the driving deck and repave the roadway.

When are the upcoming Sumner Tunnel closure dates?

MassDOT says the tunnel is set to be closed for eight weekends between now and the end of 2023. These include weekends of the following dates, plus one more yet to be scheduled:

  • Sept. 15
  • Sept. 22
  • Sept. 29
  • Oct. 20
  • Oct. 27
  • Nov. 3
  • Nov. 10

As for the summer 2024 full closure, those dates haven’t been finalized, but travelers can plan on it being closed in July and August beginning after July Fourth and ending before Labor Day.

How can I get to Logan Airport when the Sumner Tunnel is closed?

Since the Sumner Tunnel runs one way from Logan Airport to the North End, getting to the airport during the tunnel closure is not as challenging as getting from the airport.

Most traffic will be detoured into the Ted Williams Tunnel and onto the Tobin Bridge to connect with Interstate 93. Those leaving Logan Airport and heading north will be directed along Routes 1, 1A and 16 to I-93. MassDOT promises extensive signage throughout the region to guide motorists through the confusion.

The alternate routes and alternate modes of transportation remain the same as during the full closure: MassDOT suggests that travelers plan for extra travel time ahead of flights in the case that there are delays. The Blue Line, Silver Line, water ferry and Logan Express are recommended as alternatives to driving.

Why aren’t the Blue Line, buses and ferry free during these weekend closures?

MassDOT officials explain that unlike the full closure, the weekend closures are not continuous and are scheduled intermittently throughout the next several months. These closures do not impact weekday commuters and business travel and disruption has been minimized with well-established detour routes.

How have the Sumner Tunnel closures affected traffic?

During the full closure, motorists were warned about potential gridlock. Many heeded the DOT’s advice and either chose not to drive or took alternate transit. As a result, the traffic congestion was not as bad as many feared it would be.

MassDOT expects delays during weekend closures to be like those experienced during prior weekend closures, which varied depending on weather and other outside factors.