2018 Program News

2018 Program News

  • 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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    Order: 8.2

  • Northbound SR 99 closed through Seattle Saturday evening for Seafair Torchlight Run

    This Saturday, July 28, northbound SR 99 will close for the Seafair Torchlight Run from 4:30 to 7:30 p.m. between the West Seattle Bridge and Harrison Street, just north of the Battery Street Tunnel. All southbound lanes will remain open.
     
    This map shows the entire route and additional city streets that will close for the run, which will be followed by the Torchlight Parade at 7:30 p.m.
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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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    Order: 8.4

  • This weekend’s southbound viaduct closure previews the big traffic challenge still to come

    First, a short closure and a small shift

    This weekend, contractor crews working for WSDOT will close southbound State Route 99 in order to pour a new concrete roadway near Seattle’s stadiums. Crews will close southbound SR 99 between the south end of the Battery Street Tunnel and the West Seattle Bridge from 9 p.m. Friday, June 22 through 6 a.m. Sunday, June 24.

    When the highway reopens, drivers will move to a new, short stretch of highway just south of the viaduct. Getting this roadway in place is important work that must occur before the SR 99 tunnel can open to drivers. 

    Below: the yellow outline is southbound SR 99 today. The green outline is southbound SR 99 after the traffic shift. The spur on the right side is the South Atlantic Street off-ramp, which will start earlier and lengthen slightly.

    Southbound SR 99 today through SoDo Seattle

    Southbound SR 99 after closure shifts traffic to new lanes

    Beyond the weekend work – a much bigger closure

    This weekend work is a small preview of what it will take to realign SR 99 into the new tunnel to get the tunnel ready to open.

    Ramps and a permanent SR 99 must be built over the current SR 99 roadway. This means WSDOT must close SR 99 through Seattle to complete the work that opens the tunnel to traffic. We estimate it will take three weeks of construction – which means three weeks with no Alaskan Way Viaduct and no tunnel. This blog post explains more.

    We don’t have a date yet for the three-week closure as a date depends on the timing of tunnel work. Currently the tunnel contractor is testing operational and safety systems to make sure the tunnel can operate safely. At this point in time, we estimate the tunnel could open later this fall. We will give drivers about a month’s notice before we close the viaduct forever and begin the three weeks of critical ramp and realignment construction.

    Three weeks of viaduct closure, plus additional time for ramp closures

    In addition to the three solid weeks of no viaduct/no tunnel, the southbound SR 99 off-ramp to South Atlantic Street will close one week early. This ramp provides access to I-5, I-90, SODO and the stadiums.  

    After the tunnel opens, the new northbound off-ramp into downtown could take up to two additional weeks to complete. Northbound drivers who don’t want to use the tunnel can continue to exit SR99 at South Spokane Street and take city streets into downtown. It will be a rough period for drivers as there could be up to six weeks of traffic impacts to Seattle.

    This map sequence shows how the viaduct closure and tunnel opening will play out.

    There’s time to plan

    When the closure starts (again, we will give about a month’s notice), we will need everyone’s help to keep traffic moving. From past closures, we know shutting down the viaduct has a  region-wide effect. So we are asking everyone to start thinking of potential alternatives now to help you later.

    Using available tools and having a game plan will be vital during the closure. We will have much more information about alternative ways (PDF) to keep people and goods moving as the closure approaches.

    It’s an exciting time here at WSDOT as we approach our end goal of replacing the aging and seismically unsafe Alaskan Way Viaduct with a much safer tunnel. Keep following our program website and program Twitter account for more information as we move closer to opening the tunnel and tearing down the viaduct.

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    Order: 8.5

  • Plan ahead for SR 99 closures this weekend

    Drivers should allow for extra travel time this weekend as parts of SR 99 will close through Seattle. South of the stadiums, the SR 99 Connections Project will reduce both directions of SR 99 to one lane on Saturday, June 9, so crews can dig large sign foundations for the future SR 99 tunnel.

    On Sunday, June 10, the Rock ‘n’ Roll Marathon will close all lanes of northbound SR 99 between the West Seattle Bridge and Green Lake, along with off-ramps on Interstate 5 and SR 520. These closures will last until early afternoon.

    Details for the closures:

    Saturday, June 9

    • 3 a.m. to 5 p.m. – Northbound SR 99 will be reduced to one lane between South Lander Street and Holgate Street.
    • 3 a.m. to 10 p.m. – Southbound SR 99 will be reduced to one lane between Holgate Street and South Lander Street.

    Sunday, June 10

    • 4:30 a.m. to 2:45 p.m. – All lanes and ramps of northbound SR 99 between South Spokane Street/West Seattle Bridge and West Green Lake Way will be closed.
    • 6 a.m. to 11:15 a.m.
      • The northbound I-5 off-ramp to Lakeview Boulevard will be closed.
      • Two left turn lanes on the I-5 off-ramp to Mercer Street will be closed.
      • The westbound SR 520 off-ramp to Roanoke Street/Harvard Avenue will be closed.
      • Seattle city streets are also closing for the race.


    Tools to navigate traffic
    Drivers can get real-time traffic information on their phone with the WSDOT traffic app, by tracking the WSDOT traffic Twitter feed, and get advanced information from WSDOT’s Seattle Area Construction Page. Please remember to never check your phone while driving.

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  • Temporary Alaskan Way taking shape near tunnel’s south portal

    For decades, surface Alaskan Way stretched along the downtown waterfront, connecting travelers to the waterfront piers and providing north-south passage through downtown.

    Streetview of Alaskan Way from 2008 showing western position relative to viaduct

    Alaskan Way north of Seneca Street from 2008, via Google Streetview

    Since 2011, the street has been neatly squeezed in between the Alaskan Way Viaduct’s concrete footings. It was shifted to this alignment to clear space for SR 99 tunnel and other construction along the waterfront, but this location was always meant to be temporary. Eventually, the land Alaskan Way currently occupies would need to be cleared to allow for viaduct demolition.

    With demolition now on the horizon, we’ve begun restoring the street to its traditional location. Crews will continue this work over the summer and shift the street back to the west of the viaduct later this year, before the new SR 99 tunnel opens. The preparation for this shift is becoming visible as crews rebuild the roadway.

     

    The restored Alaskan Way will look much like it did the first time around. It will generally have two lanes in each direction, providing access to Colman Dock and waterfront businesses and buildings. Near the viaduct demolition work zone, the road may be narrowed to one lane in each direction, but access to Colman Dock and other properties will always be preserved.

    This configuration will remain in place until the Waterfront Seattle Project builds a new, permanent Alaskan Way in the footprint of the viaduct.

    South portal update

    A little farther south of this stretch of new pavement, an aerial view captures work building the roadways near the tunnel’s south portal. This view from the Columbia Tower shows the alignment of ramps and roadways coming into focus.

    Aerial view of the tunnel south portal

    The future ramps at the tunnel’s south portal cross what is today southbound SR 99 (click for bigger version)

    You can watch this road work from the construction camera we have mounted atop the tunnel’s south operations building. This south portal work is part of the SR 99 Connections Project, which is currently performing utility and roadwork on East Frontage Road South, between South Royal Brougham Way and South Atlantic Street.

    Crews hope to complete as much work as possible before the tunnel is ready to open. The final ramp connections, as you can tell from that map above, will go across the SR 99 mainline. So when the tunnel is ready, we will need to close SR 99 for approximately three weeks to realign the highway and connect it to the tunnel. We do not have a date for the closure yet, but we will be able to provide notice four to six weeks in advance.
     

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    Order: 9.0

  • Kiewit wins contract to demolish the viaduct

    Today, Kiewit Infrastructure West Co. was named the apparent-best-value contractor for the project that will demolish the viaduct, decommission the Battery Street Tunnel and reconnect city surface streets just north of the new SR 99 tunnel.

    The project’s design-build contract, which includes both design and construction services, is valued at $93.7 million. Kiewit submitted the apparent-best-value bid – a combination of points received for their technical proposal and their price.

    Timelines for the work will emerge after the contract is finalized and the contractor receives approval to begin design work. After that point, WSDOT will be able to share more specifics about how demolition and decommissioning will proceed.

    Last year we combined three projects into one in order to save construction time and reduce risk, so this project entails more than just demolishing the Alaskan Way Viaduct. Kiewit will be responsible for:

    • Removing the Alaskan Way Viaduct.
    • Removing the Columbia Street and Seneca Street ramp structures.
    • Decommissioning the Battery Street Tunnel, removing utility and mechanical systems, sealing the entrances and filling the tunnel.
    • Raising Aurora Avenue North to grade between Harrison Street and Denny Way, rebuilding the street, and reconnecting Thomas and John streets across Aurora Avenue North.
    • After viaduct demolition is complete, restoring waterfront roadways, sidewalks, street lighting and other elements to a temporary condition until the City of Seattle builds the new waterfront.

    Demolition cannot start until the tunnel opens to drivers, which could be as soon as this fall.

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    Order: 8.7

  • Sprucing up the north portal

    As we’ve mentioned before, the area surrounding the SR 99 tunnel’s north portal has changed a lot over the course of the project. Nearby cranes indicate that there’s still lots of construction in the area, but Seattle Tunnel Partners’ work is beginning to wind down.

    Last month, following years of utility and other construction, STP began restoring surface streets near the north portal. This work is occurring south and west of STP’s work zone, and includes sidewalk and street restoration.

    Closeup view of two crew members installing form work on Thomas Street
    Crews set up forms in preparation for paving Thomas Street near the tunnel's north portal.

    As roadway restoration continues, crews are building the remaining section of the tunnel’s north operations building. After building out the space that previously housed the tunneling machine’s disassembly pit, crews built the framework for the tunnel’s north operations building. They’re now working on the interior of the building.

    View of the tunnel's north operations building with street restoration in front
    Crews rebuild the tunnel's north operations building behind Thomas Street restoration.

    The latest notification for street restoration is available on our construction notifications page. You can also follow progress at the north portal on our construction cameras page.

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    Order: 8.8

  • Viaduct and Battery Street Tunnel closed this Sunday morning for bike ride

    Parts of northbound SR 99 will close from 6 to 11:30 a.m. this Sunday, April 8 between South Spokane Street and Bridge Way North in Fremont. This closure is part of the Emerald City Ride. Details for the closure:

    • 6 – 11:30 a.m. - Northbound SR 99 closed between South Spokane Street and Western Avenue.
    • 6 – 9:30 a.m. - Northbound SR 99 closed between Western Avenue and Bridge Way North.


    In addition, the bike ride will close the I-5 express lanes 6:45 – 10 a.m. Follow WSDOT Traffic on Twitter for updates on highway openings.

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    Order: 9.2

  • One year since Bertha’s final breakthrough

    One year ago, with a roar of water and concrete tumbling, the tunneling machine Bertha broke through into the disassembly pit, completing her 1.7-mile journey under downtown Seattle. It was and remains a remarkable engineering achievement.

    At the time, Seattle Tunnel Partners was working on the double-deck highway inside the tunnel and had completed about half of the upper roadway deck. Since Bertha’s dramatic breakthrough, the machine has been fully disassembled and crews have finished building the roadways and walls inside the tunnel.

    What happened to Bertha?

    The machine needed to be removed from the tunnel so crews could finish the tunnel’s roadways. STP spent four months disassembling the machine, cutting it up into pieces small enough to be lifted out by crane. Roughly 8,300 tons of machinery were hauled out of the disassembly pit, to be repurposed or recycled. Approximately 6,850 tons of metal were sent to be recycled, but pieces of Bertha’s signature cutterhead were donated to the Port of Seattle and cutting tools and the machine’s control panel were given to Seattle’s Museum of History and Industry.

    Bertha is no longer around but you can relive her breakthrough moment with our drone video:

    A year in tunnel progress

    Since Bertha placed the last tunnel ring, crews have made great progress on the structures and systems inside. The roadways and walls inside the tunnel are done, with the last of the roadway panels that make up the tunnel’s northbound (lower) deck placed last month. Crews are hard at work installing the electrical, ventilation and other systems that will make the tunnel functional and safe.

    At the north and south portals, all signs of Bertha’s support equipment and the large pits that bookended the machine’s journey have disappeared. Crews have covered the launch pit and are preparing to build new city streets and intersections. The disassembly pit at the north end has been covered and the final section of the north operations building is taking shape on the surface.

    Other highlights of construction progress since Bertha’s breakthrough:

     

    While the past year has seen impressive progress, there’s still plenty of work left to do. Before the tunnel opens, crews must finish installing the tunnel’s mechanical, electrical and plumbing systems, then test them to ensure they function properly. Stay tuned as we continue to report contractors’ progress building toward the tunnel’s opening, which could happen as early as this fall.

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    Order: 8.9

  • The roads are installed – now it’s time to finish the tunnel’s smart systems

    A double-deck highway now runs end to end inside the new SR 99 tunnel. Earlier this month, contractor Seattle Tunnel Partners (STP) installed the last of the 1,152 road panels that together form the lower (northbound) roadway.

    Now crews are installing and testing the tunnel’s operational and safety systems. It’s a big job. Inside the tunnel there are:

    • More than 300 cameras to monitor traffic and security at all times as part of an incident-detection system.
    • Automatic ventilation systems designed to keep air quality and visibility high.
    • Automated sprinkler systems designed to put out a fire quickly at its source.

    Together, these systems will make the SR 99 tunnel one of the "smartest" tunnels ever built. This video explains how the critical air quality and fire safety systems work together:

    Thousands of components that make up the safety and operational systems will be tested at least three times – once to make sure they work, then to make sure they work as a system, then together with other systems to make sure all systems are integrated and functional. After the systems are all certified, STP will hand the tunnel over to the Washington State Department of Transportation so a different contractor can realign SR 99 and build the final ramp connections to and from the tunnel.

    WSDOT estimates the tunnel may open to traffic as early as this fall. Stay tuned to our website and our program Twitter account for more updates as work progresses.

    By the miles:

    The SR 99 tunnel has approximately:

    • 95 miles of electrical wiring
    • 21 miles of sprinkler pipes
    • 15 miles of lights
    • 13 miles of fiber optic cables
    • 8 miles of linear heat detectors
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  • Viaduct inspection closure complete, highway is open

    SAT 4:30 PM UPDATE: Inspection complete and viaduct is open. No closure on Sunday. 

    The Alaskan Way Viaduct will close the weekend of March 24–25 for the twice-yearly inspection WSDOT conducts to keep the aging roadway safe for everyday use. Both directions of State Route 99 will close between South Spokane Street and the north end of the Battery Street Tunnel.

    Closure details:

    • SR 99 closed between South Spokane Street and the north end of the Battery Street Tunnel.
    • Highway closed 6 a.m. - 6 p.m. Saturday, March 24 and 6 a.m. - 6 p.m. Sunday, March 25.

    Travelers will need to take an alternate route during the closure weekend and expect possible delays in the area.  If inspection work finishes early and the road can reopen before 6 p.m. Sunday, we will update this post and share via our Twitter account.

    These closures are conducted every March and October so engineers can closely inspect the viaduct. Take advantage of WSDOT’s travel tools and follow WSDOT Traffic on Twitter for updates on traffic in the Puget Sound region.

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    Order: 9.3

  • The disappearing signs of the SR 99 tunnel

    It’s been almost a year (April 4) since the tunneling machine Bertha broke through into the disassembly pit near Seattle Center. Today all visible signs of the machine and the large pits that bookended its 1.7-mile journey beneath downtown Seattle are gone.

    At the south end, the launch pit is now a smooth plane that will later become the roads and ramps connecting the tunnel to SODO, downtown and the Seattle waterfront:

    Camera view of the tunnel south portal with Safeo Field in distance at left

    At the tunnel's north end, the machine’s disassembly pit has been filled up to the surface, and now the final portion of the tunnel's north operations building (the building with the yellow ventilation stacks) is being built above it:

    The steel frame of the final part of the operations building being constructed

    Zooming back and you can clearly see where the closed block of Sixth Avenue North between Harrison Street (in the foreground) and Thomas Street (behind the operations building) will be rebuilt:

    North portal construction zone showing the disassembly pit fully covered

    Once completed, Sixth Avenue North will provide a north-south connection between Mercer Street and Denny Way, with an on-ramp to SR 99 southbound and the new tunnel. You can follow construction progress on our construction cameras page.

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    Order: 9.5

  • Battery Street Tunnel and portion of SR 99 closed this Sunday morning

    City of Seattle crews will close SR 99 in both directions 6 – 11 a.m. Sunday, March 4 between the south end of the Battery Street Tunnel and North 45th Street. This closure is part of the Hot Chocolate Run. Details for the closure:

    • 6 – 10:25 a.m. - Southbound lanes closed between North 38th Street and the south end of the Battery Street Tunnel.
    • 6 – 11:15 a.m. - Northbound lanes closed between the south end of the Battery Street Tunnel and North 45th Street.


    Several city streets are also closing. Check here for a complete list.

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    Order: 9.5

  • New construction camera will capture south portal's ramps

    We’ve installed a new time-lapse camera to capture work on the SR 99 Connections Project, which will finish building the ramps and roads that connect SR 99 to the new tunnel.

    Seattle Tunnel Partners has completed some of this work, and the remaining work will occur in their existing work zones at the tunnel portals (near the stadiums in the south and near Seattle Center in the north). A new contractor, Scarsella Brothers Inc., will complete this work.

    Our newest construction time-lapse camera, "SR 99 Connections South," captures a wide view of the tunnel’s south portal (click to see the camera):

    Screen capture of web camera view of tunnel's south portal, with orange circle around concrete tunnel entrance

    The circled structure above is where southbound traffic will exit the tunnel. The rendering below shows that same tunnel exit in relation to the completed south portal. 

    Computer rendering of ramp configuration when all construction is done

    SR 99 Connections will start work this month along East Frontage Road South and South Royal Brougham Road, just to the west of Safeco Field. Crews will be installing drainage, illumination and signals, as well as building roadway, curbs and sidewalks. Crews are scheduled to complete this work by the end of May.

    If you live or work near the north end or south end construction areas, you can join the SR 99 Connections construction email update list by sending an email to viaduct@wsdot.wa.gov

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    Order: 9.6

  • Transforming Bertha's finish line

    The large pit north of Harrison Street that was the tunneling machine Bertha’s finish line has seen a series of dramatic transformations in the past few months. What was once a 90-foot-deep excavation to the west of SR 99/Aurora Avenue North will soon be entirely covered by a concrete lid, capping the future roadways and tunnel maintenance and systems corridors built within.

    In early January crews placed 10 girders across the pit. These girders, each 70 feet long and weighing 35 tons, will support the final section of the north portal operations building (the building with the four yellow ventilation stacks) that will be built atop the pit.

    This week, crews placed rebar and poured concrete to form a lid across the girders, burying the pit entirely from view.

     
    LEFT: The disassembly pit being built in 2014 (looking north)
    RIGHT: The disassembly pit on January 26, 2018 (looking north)

     

    Crews first began excavating the 450-feet-long and 90-feet-deep pit in 2013, in preparation for the completion of tunnel mining. Bertha broke through the pit's southern wall on April 4, 2017. Crews then used that space as the staging area for dismantling the 8,000-ton machine, a tremendous effort which they completed in August.

    Once the final piece of the machine was gone, the pit was ready for its second use: becoming part of the tunnel itself. Since August crews have been building walls and decks within the pit that will connect the bored tunnel’s roadways to the short section of cut-and-cover tunnel just to the north. Building these structures has slowly obscured the disassembly pit from view of our construction camera.

    In the coming weeks and months crews will begin constructing the final section of the operations building. They will also restore the block of Sixth Avenue North that has been used as a construction staging area for the north portal work.

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    Order: 9.7

  • Highway construction inside the tunnel moves north

    This week, Seattle Tunnel Partners shifted gears and moved its road-building operation north for the final 3,000 feet of lower roadway inside the SR 99 tunnel.

    Unlike the southbound (upper) roadway, which was built using concrete pours, the northbound (lower) roadway comes together one 22-ton panel at a time. The pre-made panels are trucked into the tunnel, lifted with a specialized crane and joined together to create a functioning highway.

    This new time-lapse video shows how the road comes together:

    STP installed the first 6,000 feet of lower roadway by hauling the panels from the south portal to a point roughly under Virginia Street and First Avenue. From there, they worked their way south, installing panels as they went. Following the recent completion of the upper roadway at the tunnel’s north end, crews can now deliver panels via the north portal and work south-to-north to finish the final 3,000 feet of lower roadway.

    There’s still a lot work ahead before the tunnel is ready for traffic. STP must complete installation and testing of all the operational and safety systems that will make the tunnel function. You can follow the work on our tunnel progress tracker.

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    Order: 9.8

  • Looking forward to a busy 2018

    There’s a lot to be excited about as the Alaskan Way Viaduct Replacement Program enters 2018. We’re working toward several important construction milestones.

    Pushing toward tunnel completion

    STP made great progress last year. They finished tunneling, disassembled the tunneling machine and completed the southbound (upper) roadway inside the tunnel. Based on STP’s newest schedule (PDF), the tunnel could open to drivers as soon as this fall. Our goal is to safely open the tunnel to traffic as quickly as possible and begin removing the Alaskan Way Viaduct, but it’s too early to accurately predict a tunnel opening date. Safety and quality remain our top priorities, and will continue to guide all work on the program.

    A significant amount of work remains between now and tunnel opening. Crews must complete construction of the roadway within the tunnel, and finish installing many interconnected systems that will be required to operate the tunnel. They also must complete a series of thorough tests and certification by the Seattle Fire Department to ensure the systems are working properly. This includes testing approximately 5,000 individual components and nearly 90 tunnel systems. 

    As always, WSDOT will continue to closely monitor STP’s work. You can do the same at our construction tracking page.

    The road to tunnel opening

    As STP continues their work, construction of final ramp and highway connections to the tunnel is set to begin. The SR 99 Connections Project will build the final connections between the existing highway and the tunnel. Scarsella Bros., Inc. is the contractor for this work, which will be performed under a $22.6 million contract awarded by WSDOT last month.

    Scarsella will break ground soon and continue their work throughout this year. When the tunnel is ready to open, SR 99 through downtown Seattle will be closed to traffic for approximately three weeks. Ramps to and from SR 99 will also be affected during this work. The final connections to the tunnel can only be built after the viaduct has been closed because crews must demolish portions of the current roadway to realign SR 99. When these roadway connections are complete, drivers will begin using the new tunnel.

    We recognize that this temporary closure of SR 99 will affect the entire region. We’re also aware that the tunnel is one of many projects under construction in downtown Seattle. We will continue to coordinate construction activities with the City of Seattle, Port of Seattle and King County to minimize disruptions to the public. As we always do during major highway closures, we will coordinate with our partner agencies to spread the word, and help keep people and goods moving while crews complete their work.

    After the tunnel opens

    After the tunnel opens to drivers, we can begin the challenging task of demolishing the Alaskan Way Viaduct. The demolition contractor will also be responsible for decommissioning the Battery Street Tunnel and reconnecting surface streets across Aurora Avenue North. These three projects were combined under a single design-build contract to shave off approximately one year of cumulative construction time. 

    As we explained this summer, the contractor will determine how the viaduct will be demolished within parameters set in the contract. We plan to select a contractor in late spring, and will share the demolition plan and schedule after the contractor is chosen.

    We’re excited about the work that lies ahead in 2018. Stay tuned for new photos, videos and social media updates as we push toward tunnel opening.

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    Order: 9.9