North surface streets

North surface street connections

Filling and sealing the Battery Street Tunnel provides an opportunity to rebuild and reconnect three streets in South Lake Union previously cut off by SR 99. Crews will rebuild Aurora Avenue North between Harrison Street and Denny Way, filling in the Battery Street Tunnel trench and reconnecting Harrison, Thomas and John streets east-west.

Aerial view of north end of tunnel with construction area highlighted in orange

SR 99 cuts off east-west travel routes between South Lake Union and Seattle Center

Scope of work

Construction will begin in February 2019 and is scheduled to be complete in mid-2020. The major elements of this work are:

  • Opening Harrison Street east-west (after the SR 99 tunnel opens; exact timing TBD).
  • Filling in the trench approaching the Battery Street Tunnel.
  • Rebuilding Aurora Avenue North between Denny Way and Harrison Street, including dedicated transit lanes.
  • Reconnecting Thomas and John streets, compatible with future green street improvements on Thomas Street.
  • Electrical duct bank, gas line and water line work.
  • Paving, sidewalks, striping and landscaping.


Construction impacts

The work will be conduced in phases that will keep at least one lane of traffic open in both directions on this stretch of Aurora Avenue North. During construction, neighbors and travelers should expect:

  • Concrete barriers will be used to separate travel lanes from work areas.
  • Dust will be controlled through water misting.
  • Temporary detours for people walking, biking and driving.
  • Temporary building and parking access restrictions according to previously negotiated Temporary Construction Easements.
  • Work will be done primarily during daytime hours to minimize noise impacts.
  • Increased truck traffic while crews close and fill the north portal. This will require hundreds of truck trips to deposit embankment material.
  • Typical construction impacts such as increased dust, noise, vibration, and truck activity.


Aurora Avenue North conceptual channelization:

When the project is complete, Aurora Avenue North will have two lanes in each direction, plus transit lanes to help buses get to and from SR 99. 

Lane diagram showing Aurora Avenue North between Denny Way and Harrison Street