Latest Program News

  • Details of SR 99 northbound closure this weekend

    We will be closing SR 99 northbound this weekend in order to install sign bridges over the highway and conduct some paving. The closure starts tonight but reopens in phases, so here's what to expect:

    Map of highway closure

    Tonight: SR 99 northbound closes at 9 p.m.

    • Northbound SR 99 closes from South Spokane Street to the south end of the Battery Street Tunnel.
    • Two local streets near the stadiums also close: East Frontage Road South (from South Atlantic Street to South Royal Brougham Way), and South Royal Brougham Way (from First Avenue South to East Frontage Road South).
    • Note: the southbound SR 99 off-ramp to South Atlantic Street remains open throughout the weekend.

    Saturday, 9/22: Part of highway reopens 

    • The local streets (East Frontage Road South and South Royal Brougham Way) reopen by the evening; exact time depends on work progress.
    • The northbound SR 99 on-ramp at South Royal Brougham Way also reopens.
    • SR 99 northbound reopens from South Royal Brougham Way north to the Battery Street Tunnel.
    • Highway from South Spokane Street to the stadiums remains closed.

    Sunday, 9/23: Limited northbound closure remains 

    • SR 99 northbound remains closed from South Spokane Street to South Royal Brougham Way.
    • The northbound SR 99 on-ramp near the stadiums remains open.

    Monday, 9/24: Closure ends at 5 a.m.

    • The rest of northbound SR 99, from South Spokane Street to South Royal Brougham Way, reopens.

    This closure will allow crews to install sign bridges and VMS signs over the highway that will become part of the SR 99 tunnel’s traffic management system. Closing the on-ramp and local streets will allow crews to install drainage and pave the intersection that leads to the on-ramp.

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  • Parking removal along Alaskan Way beginning Sept. 24

    This fall, we are moving Alaskan Way out from beneath the viaduct. This switch will help keep people moving along the waterfront during the #realign99 closure and afterward during viaduct removal. Alaskan Way will run along the waterfront between the piers and the viaduct, with two lanes in each direction.

    Graphic showing the Alaskan Way Traffic Switch
    Graphic showing Alaskan Way configuration after the traffic switch (click the image for larger version).

    Next week, crews will begin permanently removing parking spaces in front of the waterfront piers, between Yesler Way and Pike Street. Once removed, parking will be replaced with new traffic and pedestrian striping. Some of this work will be done on weekday nights to reduce impacts to the waterfront during the day. The road will be closed to drivers as crews complete this work. Access will be maintained for charter buses, passenger ferry pick-ups/drop-offs and deliveries. When the striping and traffic signal work is complete, the traffic switch to the new alignment will occur, currently scheduled for mid-October.

    Crews will add angled parking beneath the viaduct as part of this work. Our goal is to install as many spaces as possible between South King and Union streets beneath the viaduct. Striping these spaces may take several weeks after the traffic switch occurs, meaning there will be a period of time when both the new and current parking spaces are not available for use. Once the spaces are in place, the contractor will be allowed to close them as needed to complete their work to remove the viaduct.

    A free Waterfront Shuttle service provides free hop-on, hop-off rides to any of the 11 stops near downtown attractions and along the historic waterfront. The shuttle runs approximately every 20 minutes from 10 a.m. to 8 p.m., seven days a week. For more information about the shuttle and parking garages along the waterfront, visit

    Other construction along the waterfront

    As crews continue their work, other waterfront projects are also preparing for the viaduct’s removal. Over the next couple of months, private utility companies will move utilities currently running on and beneath the viaduct. Waterfront visitors and travelers should expect work in various locations between South King and Pike streets, primarily in small areas and for relatively short durations, involving single lane closures and localized parking restrictions. For more information on other projects along the waterfront, visit


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  • SR 99 tunnel to open in early 2019 after three-week #Realign99 highway closure

    Get ready – the new SR 99 tunnel beneath Seattle will open in early 2019, offering a direct route from the stadiums to the Space Needle. But before we can open the tunnel, we must #realign99. This closure – the longest major highway closure to ever hit the Puget Sound Region – will begin on Jan. 11, 2019.

    This traffic disruption is unavoidable. Closing SR 99 through Seattle for approximately three weeks allows crews to complete building the highway and the eight new ramps that will allow travelers to enter and exit the tunnel.

    During the closure, both the viaduct and the tunnel will be closed. Drivers should expect up to six weeks of region-wide congestion. In addition to the three-week closure:

    • The southbound SR 99 off-ramp to South Atlantic Street will close a week earlier, on Jan. 4, 2019.
    • A new off-ramp from northbound SR 99 to South Dearborn Street will require one to two additional weeks of work after the tunnel opens.

    Closure timing

    When Seattle Tunnel Partners finished disassembling the tunneling machine Bertha in 2017, we estimated the tunnel would be open in early 2019. While there was optimism this date could be moved up, a number of factors influenced the decision to stay with the early 2019 date:

    • Construction progress: WSDOT has several contractors that must complete work before the #realign99 closure can begin.  Some of this work, like road striping, is weather dependent.
    • Public notice: Starting in January ensures that contractors’ work will be complete and we can provide you with a specific date much farther in advance. Your help will be critical to keeping the region moving during the closure, and more notice means more time to plan.
    • Avoiding the holidays: WSDOT and its partner agencies are committed to keeping people and goods moving during the busy holiday season. Avoiding a major highway closure between Thanksgiving and New Year’s Day helps achieve this goal. There are also fewer major Seattle events in early 2019 than there are during the last quarter of 2018.


    Get ready, make a plan

    The #realign99 closure will test travelers all around the region. During the closure the 90,000 drivers who normally use the Alaskan Way Viaduct will have to find another way to get to or through downtown Seattle. Congestion and delays will affect both major highways and local streets as drivers who normally use the viaduct look for alternative routes.

    We and our partner agencies have been planning for this closure and will implement a number of strategies to keep people and goods moving. These measures include increased West Seattle Water Taxi trips, more incident response teams on the roads, and signal timing changes on local streets. But we will also need help from commuters and employers to keep the region moving. Visit our #realign99 page for more information and resources for travelers and employers.

    A major safety investment for our highways

    We are replacing the seismically vulnerable viaduct with a modern tunnel equipped with state-of-the-art operational and safety systems. We will have more to share in the coming weeks about pathways to and from the tunnel. Per the Legislature’s decision, the SR 99 tunnel will be tolled as part of the project’s financing plan. The tunnel will be free to use when it first opens.

    Additional details about the tunnel and the future tolling of the tunnel can be found at

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  • SR 99 Tunnel Project update

    Seattle Tunnel Partners continues their testing of the 90 safety and operations systems in the SR 99 tunnel and operations buildings. Yesterday evening, during one of those tests, pressurized air forced a door open and caused some drywall damage in the north operations building. No one was injured and there was no structural damage. This is precisely why the contractor has an extensive testing protocol in place. We are investigating the cause and will make adjustment to design and operations, as needed.

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  • Keeping the air fresh: Testing the tunnel’s ventilation systems

    Seattle Tunnel Partners is making good progress testing the operational and safety systems inside the new State Route 99 tunnel. Tests of the ventilation systems are now underway, including the giant fans connected to the tunnel’s distinctive yellow ventilation stacks at both ends of the tunnel. This video shows the ventilation tests in progress:

    The ventilation system is just one of the many systems inside the SR 99 tunnel undergoing testing to make sure the tunnel functions as designed. This video shows how the safety systems work together to keep travelers safe.

    Testing to make sure the tunnel’s safety systems work together, a step known as integrated systems testing, is still to come. Additional work is also taking place outside the tunnel to prepare for moving Alaskan Way out from under the viaduct and to get ready for the three-week #realign99 closure of SR 99 needed to open the tunnel.

    Stay informed about 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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