Advisories/Updates

  • Weekend of SR 99 closures is underway

    UPDATE: As of 5:30 p.m., Saturday, March 28, the Alaskan Way Viaduct is now open from South Spokane Street to the south end of the Battery Street Tunnel. Bridge crews completed all of their work during today’s viaduct inspection, so tomorrow’s inspection closure is canceled. SR 99 remains closed from the Battery Street Tunnel to Valley Street until 5 a.m. Monday, March 30.

    Highway construction, utility work and a regular inspection of the Alaskan Way Viaduct have closed portions of SR 99 through Seattle this weekend. Closures along both directions of SR 99 began at 7 p.m. Friday and will last until 5 a.m. Monday.

    SR 99 closure details
     
    7 p.m. Friday, March 27, until 5 a.m. Monday, March 30

    • Seattle Public Utilities crews will close two northbound lanes and one southbound lane of SR 99 between Ward Street and Highland Drive from 7 p.m. Friday to 5 a.m. Monday. 
    • WSDOT and SDOT contractor crews will close SR 99 between the Battery Street Tunnel and Valley Street from 10 p.m. Friday to 5 a.m. Monday.


    6 a.m. to 6 p.m. Saturday, March 28, and Sunday, March 29

    • WSDOT bridge inspection crews will conduct a scheduled inspection of the Alaskan Way Viaduct between South Spokane Street and the Battery Street Tunnel.


    Westbound I-90 closure

    The SR 99 closures are part of a busy weekend of highway construction in the region. Drivers heading across Lake Washington from the Eastside will see westbound Interstate 90 detoured to the express lanes as crews upgrade tunnel operations systems inside the westbound Mount Baker and Mercer Island tunnels.

    11 p.m. Friday, March 27, until 5 a.m. Monday, March 30

    • Contractor crews will shift all westbound I-90 traffic between Bellevue Way and Rainier Avenue South to the express lanes from 11 p.m. Friday to 5 a.m. Monday. 
    • Drivers wishing to access Mercer Island will need to exit westbound I-90 at East Mercer Way. There are no westbound exits to Mercer Island from the express lanes. 
    • Those wishing to travel from Mercer Island to Seattle should enter the express lanes at 77th Avenue Southeast or Island Crest Way. 
    • Westbound I-90 drivers will be unable to exit to Rainier Avenue South and should follow the signed detour via Fourth Avenue South and South Dearborn Street. 
    • Drivers needing to transport flammable materials westbound across Lake Washington must use alternate routes such as Interstate 405 or state routes 520 or 522. 
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  • March 27 project update: Final lift approaches

    Seattle Tunnel Partners is nearly ready to lift the SR 99 tunneling machine’s front end to the surface for repairs. On Thursday, the massive red crane that will make the lift was rolled into place above the tunnel access pit. Crews are now connecting rigging and will spend the weekend making final preparations to lift the 2,000-ton piece to the surface. In addition to the machine’s five-story-tall cutterhead, the section being lifted includes the motors and parts that enable the cutterhead to rotate. It also houses the main bearing and seal system that will be replaced during the repairs.
     
    Because the piece is so large, the lift could take 16 hours or longer, but there is no set schedule. Crews will take as long as necessary to prepare for and safely complete the lift. The crane doing the lifting was built by Mammoet, a firm that has performed similar lifts around the world, including the successful recovery of a Russian nuclear submarine from the bottom of the Barents Sea. Equipped with nearly seven miles of steel cable, the crane bringing Bertha to the surface is capable of lifting more than 2,400 tons. Check out our time-lapse video (links to YouTube) showing the crane’s assembly.  
     
    This will be the fourth and final lift in STP’s repair effort, which our narrated video (links to YouTube) explains in detail. To date, crews have removed three pieces of Bertha’s exterior from the pit, the largest weighing 270 tons. The first lift, which occurred on March 19, can be seen from the perspective of the crane operator in this time-lapse video (links to YouTube).
     
    You can track the action on our time-lapse camera and follow @BerthaDigsSR99 on Twitter for updates. We’ll also continue to post photos and videos as STP’s work progresses.
     
     
    The crane that will lift the tunneling machine's front end to the surface rolled into position on Thursday.
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  • March 23 project update: Third piece of tunneling machine lifted to the surface

    Seattle Tunnel Partners has successfully lifted the third piece of the SR 99 tunneling machine to the surface for repairs. Crews lifted the machine’s 90-ton right side body from the pit Monday afternoon. Like the previous two pieces removed from the pit, the right side body is part of the machine's exterior shield.

    The first lift, which occurred last week, can be seen from the perspective of the crane operator in this time-lapse video (links to YouTube).

    With the machine's upper shield removed, STP will turn their attention to the final lift: Bertha's massive cutterhead and main drive unit. Crews will use the giant red crane, called a modular lift tower, to make the 2,000-ton lift. This narrated video (links to YouTube) explains the repair plan in detail.  

     

    Crews lifted Bertha’s 90-ton right side body from the pit on Monday.

    Three pieces of Bertha's shield have been brought to the surface for repairs. 

    You can track the action on our time-lapse camera and follow @BerthaDigsSR99 on Twitter for updates. We’ll also continue to post photos and videos as STP’s work progresses. 

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Program Spotlight

  • A look inside the new-look SR 99 tunnel

    Not long ago, you might have been able to fit a five-story building inside the cavernous circumference of the SR 99 tunnel. Not anymore. From the south end of the tunnel to the back end of Bertha, the SR 99 tunneling machine, crews have filled the tunnel with long stretches of walls and roadway sections of the future underground highway. The series of photos below shows just how much the landscape inside the tunnel has changed. 

     

    In the first photo, you are looking … more