North End

North End


A significant amount of construction continues at the SR 99 tunnel’s future north portal. The 80-foot-deep pit is where Bertha, the SR 99 tunneling machine, will emerge at the end of her two-mile journey beneath downtown Seattle.

Crews are also building the connection between the tunnel and Aurora Avenue North, and new on- and off-ramps at Republican Street. Our interactive simulation shows you how this area will change during construction.

When construction is complete, drivers, pedestrians and bicyclists will be able to travel between South Lake Union and Seattle Center via three improved east-west streets across the new Aurora Avenue North.      

Postponed: Long-term lane closures on SR 99/Aurora Avenue North

We are postponing plans for long-term lane closures on SR 99/Aurora Avenue North originally scheduled to begin on Wednesday, March 11. These closures were needed to install several large sign foundations for the SR 99 North Access project. While this work must occur, it will be rescheduled to a later date in an effort to minimize impacts to the traveling public. The public will be alerted in advance of any future lane closures.

Current construction near Dexter Avenue North

To make room for SR 99 tunnel construction, crews are relocating utilities along Dexter Avenue North and Republican Street.  

During this work, Dexter Avenue North will be reduced to one lane in each direction between Harrison and Mercer streets. A separate bicycle lane will be maintained on Dexter Avenue North during peak commute times. Depending on the work activity, signs may direct bicyclists to merge with traffic during off-peak hours. 


View a map (pdf 502KB) of the work zone. Our traffic Web page also includes up-to-date closure information.   

Other construction in the area

As you've likely noticed, the north end is bustling with construction activity. In addition to tunnel construction, our partners at the City of Seattle are making great progress on the Mercer Corridor Project. We’re coordinating closely with their construction, and will continue to do so as we move forward.