Battery Street Tunnel

Filling and sealing the Battery Street Tunnel

Why close the Battery Street Tunnel

With the Alaskan Way Viaduct closed, SR 99 no longer runs through the Battery Street Tunnel. Like the viaduct, the tunnel was built in the 1950s and is seismically vulnerable. Any new or continued use of the tunnel would require prohibitively expensive renovations. Closing the Battery Street Tunnel allows WSDOT to rebuild the three-block stretch of Seventh Avenue North at the tunnel’s north end, improving east-west mobility in that neighborhood.

Scope of work

Work began on Feb. 12, 2019 and is scheduled to be complete in late 2020. The major elements of this work are:

  • Decommissioning and removing the tunnel’s utility and mechanical systems.
  • Removing hazardous materials from the tunnel.
  • Filling the tunnel and sealing its entrances.
  • Street restoration along Battery Street, including sidewalk improvements, new curb ramps, street lighting and other pedestrian improvements.

The blue-highlighted zone in the map below shows the work area for the project:

Map of Battery Street with blue highlighted area stretching from First Avenue to Borealis Avenue

Filling the tunnel

The tunnel will be filled in two phases. The lower half of the tunnel will be filled with crushed concrete from the viaduct, trucked into the tunnel or poured in through grates in the roadway above. The top half of the tunnel will be filled with a type of concrete pumped in from the surface. Click the diagram below to enlarge:

Diagram showing how the lower half of the tunnel will be filled differently than the top

Effects of construction

Construction will occur both inside the Battery Street Tunnel and on the surface street above. The first phase of work will occur mostly inside the tunnel, with little visible work on the surface street aside from short-term lane closures to give crews access to the tunnel below.

During construction, neighbors and travelers should expect:

  • Traffic lane restrictions and closures along Battery Street. Two lanes of traffic will be open during typical PM peak commutes, with up to 42 days of single-lane configuration and a limited number of night and weekend full closures.
  • Construction equipment staged at the south end of the tunnel.
  • Temporary building and parking access restrictions according to previously negotiated Temporary Construction Easements.
  • Increased truck activity on Battery Street and near the north and south portals.
  • Typical construction effects such as increased dust, noise, and vibration.
  • Local sidewalk access maintained with possible short pedestrian detours.
  • Most construction during the daytime, with occasional night work.
  • Water misting to reduce dust.
  • Occasional temporary closures of cross-street traffic.
  • Temporary parking restrictions on Battery Street and side streets for equipment staging.

How to stay informed

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Questions? Call the 24/7 program hotline at 1-888-AWV-LINE (298-5463) or send an email to