Latest Program News

  • Preparatory work begins on Alaskan Way for traffic switch this fall

    Last week marked the beginning of an important project that must be completed before the Alaskan Way Viaduct can be removed. Crews working for Kiewit Infrastructure West Co. have begun the traffic signal, striping and roadway signage work required to switch traffic on Alaskan Way from beneath the viaduct to just west of the viaduct. Alaskan Way's travel lanes were detoured beneath the viaduct years ago to accommodate construction of the seawall project and the SR 99 tunnel, which could open as soon as this fall.

    Crews will be working through late summer or early fall to restore street traffic to the west side of the viaduct. This switch will provide space under and around the viaduct for the removal work, while keeping Alaskan Way open during that construction. Implementing the traffic switch requires wiring intersections for traffic signals, installing roadway signage, and updating roadway and parking striping. 

    Crew with bucket truck pulling wire across the road just west of the viaduct

    Above: Crews working on a new traffic signal at Columbia Street.

    Crews are currently working on the west side of the viaduct, at the cross-street intersections from Yesler Way to Union Street. They are installing wooden traffic signal poles, trenching and adding underground conduits, and installing cables and traffic signals overhead.

    This work will temporarily close some parking spaces and parts of the intersections to ensure the safety of crews and the travelling public. People walking, biking and driving along the waterfront will still be able to move through the area, and business loading zones will be preserved. Kiewit’s crews are minimizing their work areas where possible in order to limit these temporary parking disruptions.

    View of roadway running parallel to the viaduct with crews working at intersection

    Above: When work is complete Alaskan Way will run here, between the viaduct and the piers.

    This work will not disrupt the new, free Waterfront Shuttle. The pilot service is providing free hop-on, hop-off rides between Pioneer Square and the Space Needle, with stops along the waterfront. Part of WSDOT’s funding commitment to Seattle’s waterfront and Pioneer Square, the shuttle runs approximately every 25 minutes from 10 a.m. to 8 p.m., seven days a week, through October 1.

    The switch of traffic from under the viaduct to west of the viaduct will happen before the three-week #realign99 closure of SR 99Keep on top of upcoming highway and street closures via our construction notices page, our program Twitter account, or by subscribing to our program email list.

     

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  • SR 99 tunnel systems testing continues

    Getting the tunnel ready for drivers is a big task. Contractor Seattle Tunnel Partners must install and test thousands of components and 90 interconnected systems that are needed to safely operate the SR 99 tunnel.

    Systems work began in March after crews completed the roadway inside the tunnel. STP is now conducting multi-layered tests of the tunnel's operational and safety systems. Pre-functional tests ensure that each piece of individual equipment works (a sprinkler head). Functional tests check that the equipment works together as a system (multiple sprinklers). Finally, integrated testing checks that multiple systems function together (heat detectors and video cameras that work with the fire suppression system).

    This video explains the complex safety systems inside the tunnel and how they work together to keep travelers safe.

    STP has completed many of these tests, including testing the sprinkler system, but has more critical work to go. STP recently submitted their latest construction schedule showing they could complete their work by late September. But because so much critical testing remains, WSDOT cannot verify this schedule.

    In the meantime, other contractors will move Alaskan Way out from under the viaduct and complete preliminary work to connect ramps and roads to the tunnel at both ends. Once the tunnel is complete and systems function as designed, we must close SR 99 through Seattle for about three weeks to realign SR 99 into the new tunnel.

    Our goal is to safely open the tunnel to traffic as soon as possible and begin removing the Alaskan Way Viaduct, but systems testing must advance before any dates for closing SR 99 or opening the tunnel can be determined.

    We recognize closing SR 99 will affect traffic around the region and we are working with the City of Seattle, Port of Seattle, King County and Sound Transit to help keep people and goods moving. We will provide about a month’s notice prior to closing SR 99 and will need everyone’s help to keep traffic moving. We’re encouraging people to start thinking about travel alternatives and make a plan for getting around when SR 99 is closed.

    Keep following our program website and program Twitter account for more information as we move closer to opening the tunnel and taking down the viaduct.

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  • When a really big tunnel needs really small trucks

    When the SR 99 tunnel opens, a fleet of tiny trucks will help WSDOT crews maintain the tunnel – traveling in places most of us will never see. While you drive underneath Seattle, your car might be just a few feet above maintenance workers doing their jobs in these bright, yellow trucks.

    WSDOT received nine new maintenance vehicles over the summer. The vehicles will move into the new SR 99 tunnel after tunnel contractor Seattle Tunnel Partners completes all tunnel systems testing and turns the tunnel over to WSDOT. The four-wheelers will travel the two-mile road beneath the tunnel’s lower roadway; the smaller, three-wheel versions can drive in the narrow corridors on the tunnel’s west side (see graphic below).

    Tunnel cross section showing the corridors on the left and bottom

    All nine trucks are electric and will be housed in the tunnel’s north operations building where they can be recharged by simply plugging them into a standard outlet.

    Bigger maintenance jobs will require bigger equipment, like bucket trucks and flatbed lift trucks. All total, more than 30 pieces of equipment will make up the tunnel maintenance fleet dedicated to traffic and maintenance inside Seattle’s newest tunnel.

    The tunnel could open as soon as this fall, after an approximately three-week viaduct closure to realign SR 99 into the new tunnel.

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