2018 Program News

2018 Program News

  • A year of progress and preparation

    It’s been a year of progress and preparation for the Alaskan Way Viaduct Replacement Program. As we get ready for a jam-packed start to 2019, here’s a quick look at highlights of the past year.

    In 2018 the SR 99 tunnel contractor, Seattle Tunnel Partners, completed the tunnel roadway and installed and tested thousands of components that together make up 90 tunnel systems. STP reached substantial completion in October and turned over control and ownership of the tunnel to WSDOT. During this time, WSDOT continued systems testing and training of tunnel operations and emergency response staff.

    While STP worked on the tunnel, other contractors began their work. At both tunnel portals, the SR 99 Connections Project contractor Scarsella Brothers began working on the eight ramps connecting the tunnel to local streets. And, in May we awarded Kiewit Infrastructure West with the contract to remove the viaduct, close and seal the Battery Street Tunnel, and rebuild surface streets near the SR 99 Tunnel’s north portal. One of their first orders of work was to shift Alaskan Way out from beneath the viaduct and restore parking in October. This new alignment allows us to keep the road open while the viaduct is demolished in 2019.

    Looking ahead to early 2019

    This work sets the table for a very exciting start to 2019. On Jan. 4, we will close SR 99 on- and off-ramps near the stadiums, and the #Realign99 highway closure begins a week later, at 10 p.m. on Jan. 11. This approximately three-week-long closure will give crews time to complete the tunnel’s ramps and realign SR 99 off the viaduct and into the new tunnel.

    A public grand opening ceremony on Feb. 2-3 will commemorate the viaduct and celebrate the opening of the new tunnel. Shortly thereafter, the new SR 99 tunnel will open, forever changing how we get to and through downtown Seattle. Shortly after that, Kiewit begins their work removing the old SR 99 route from downtown Seattle.

    Two years ago, we estimated $149 million of additional program costs would be needed due to delay in completion of the tunnel project. The request for additional funds has been partially filled in previous legislative sessions. Today we presented to the Legislature’s Joint Transportation Committee and requested $43 million to complete the program, which brings the total request to $156 million. It’s important to note that none of these additional funds will be used to pay for tunneling machine repairs. WSDOT continues to follow the tunnel project’s design-build contract to recover added expenses incurred by the tunneling delay (e.g. insurance claims and litigation).

    We have a few more years of construction and are on the cusp of many exciting milestones including opening the new SR 99 tunnel beneath downtown and demolition of the Alaskan Way Viaduct.

    — more —

    Order: 6.2

  • READ FIRST: Alaskan Way Viaduct closure details

    Full SR 99 closure in place. Full sequence below:

    10 p.m. Friday, Jan. 4: Stadium ramps closed 

    • Northbound SR 99 on-ramp at South Royal Brougham Way closes (near stadiums; connection to I-90 and I-5).
    • Southbound SR 99 off-ramp at South Atlantic Street closes (near stadiums; connection to I-90 and I-5).

    10 p.m. Friday, Jan. 11: Full SR 99 closure through downtown Seattle begins 

    • SR 99 closes both directions from South Spokane Street to the south end of the Battery Street Tunnel.
    • Battery Street Tunnel remains open with one lane in each direction. Ramps to and from Western Avenue remain open.
    • West Seattle Bridge and off-ramps to First Avenue and Fourth Avenue remain open and do not close as part of Realign99.

    10 p.m. Friday, Feb. 1: Battery Street Tunnel closes 

    • Battery Street Tunnel closes. On-ramp and off-ramp from Battery Street Tunnel to Western Avenue also close.
    • Southbound SR 99 diverted at Valley Street.
    • Local streets closed for Grand Opening Festival activities. See advisory for details.

    Early morning Feb. 4: New tunnel opens 

    • SR 99 reopens about three weeks after Jan. 11, with highway using new SR 99 tunnel. Alaskan Way Viaduct and Battery Street Tunnel remain closed. One SR 99 off-ramp remains closed (see below).

    Approx. 2 weeks later: Final ramp opens

    • New SR 99 northbound off-ramp to downtown and Alaskan Way (just south of tunnel) opens, about two weeks after SR 99 tunnel opens.

    Visit our Realign99 page for more information and resources on how to get around during the closure.

    — more —
  • Alaskan Way Viaduct removal scheduled to begin in February

    Opening Seattle’s new SR 99 tunnel early next year will set the stage for the biggest transformation of Seattle’s central waterfront in a generation. The demolition of the Alaskan Way Viaduct is scheduled to begin in February 2019 and take approximately six months to complete, as work crews move along the structure, removing it section by section.

    Our new video provides an overview of the work to come:

    The contractor conducting the work, Kiewit, has been finalizing their work plans and schedule, and we'll have new information to share on the Viaduct Demolition section of our website this week. Demolition work is unavoidably disruptive, but the waterfront, Pioneer Square, and other nearby neighborhoods will remain open throughout the project.

    Removing the viaduct, however, is just one part of the work to come. After the new tunnel opens, Kiewit will also begin filling and sealing the Battery Street Tunnel, and rebuilding Aurora Avenue North between Harrison Street and Denny Way. Those projects are both scheduled to conclude in 2020.

    Live or work near the viaduct or Battery Street Tunnel? Join us for drop-in sessions this week and next. WSDOT and Kiewit project staff will answer questions about the work to come, aided by display boards and handouts. All three sessions will have the same information, covering every part of the project.

    Tuesday, Dec. 4, 2018
    5 - 8 p.m.
    Waterfront Space
    1400 Western Ave., Seattle, WA

     Wednesday, Dec. 5, 2018
    11 a.m. - 2 p.m. 
    Waterfront Space
    1400 Western Ave., Seattle, WA

    Monday, Dec. 10, 2018
    5 - 8 p.m.
    Seattle Center, Armory Loft Room 2
    305 Harrison St., Seattle, WA

    — more —

    Order: 6.3

  • Realign99 closure plan gets tuned up, finalized

    Closing SR 99 through downtown Seattle for approximately three weeks will cause major disruptions to traffic throughout the region. It’s a challenge we don’t take lightly, and so we’ve spent many months studying and refining our plans to ensure we take the most efficient, least impactful approach.

    The results of that effort were recently finalized. The details of the closure plan we shared earlier this fall are largely the same. Mainline SR 99 will close through downtown Seattle for approximately three weeks beginning Friday evening, Jan. 11, 2019. There are, however, a few refinements to the original plan: 

    • Effective Dec. 14: Crews will reduce the length of the northbound SR 99 transit lane in SODO by approximately 1,400 feet. This will enable the contractor to repair a dip in the road at that location that would otherwise need to be repaired during the mainline closure. Starting the work early will support access to the SR 99 closure work areas and enable the contractor to focus on other critical work during the closure.
    • Effective Dec. 14: Crews will shorten the southbound right-turn lane to Harrison Street and narrow travel lanes on SR 99 near the SR 99 tunnel’s north portal. This will allow safer and better access to work areas and reduce the schedule risks associated with removing a temporary wall that supports the existing highway.
    • Jan. 4: The most notable change from the previous sequence is the date of the northbound on-ramp closure near the stadiums. This ramp, which connects approximately 12,500 vehicles each day from South Royal Brougham Way to northbound SR 99, is now scheduled to close on Jan. 4, 2019 – one week earlier than the previously announced date. This additional week will allow the contractor more time to perform critical work (including unburying tunnel on- and off-ramps) that has the potential for some unanticipated challenges, giving crews additional flexibility during the mainline closure. The southbound SR 99 off-ramp to South Atlantic Street near the stadiums will also close as scheduled at this time.

    These refinements will reduce the amount of work that would otherwise need to be completed during the mainline closure. As a result, the contractor will be in better position to timely complete work that must be finished prior to tunnel opening. A full look at the closure sequence is available at our #Realign99 page, where you’ll also find resources about how to prepare for the longest major highway closure the Puget Sound region has ever seen.


    — more —

    Order: 6.4

  • Long-closed block of Sixth Avenue North reopens

    The intersection of Sixth Avenue North and Harrison Street near Seattle Center has seen a lot of change in the past decade. Compare the intersection today to the Google Maps streetview from 2008 and the area is almost unrecognizable.

    Today we reopened the block of Sixth Avenue North between Harrison Street and Thomas Street. The area has played host to the tunneling machine Bertha’s receiving pit, and construction staging for the SR 99 tunnel’s north operations building. Our time-lapse camera captured six years of work in 40 seconds:

    More work remains to be completed in the area, including opening the sidewalk on the east side of the block. But drivers can now take Sixth Avenue North between Denny Way and Mercer Street, a helpful new connection in the area and a future pathway for getting to the new SR 99 tunnel.

    — more —

    Order: 6.5

  • Eight weeks to go until the Realign99 closure and the start of final roadwork to open the new SR 99 tunnel

    When the Alaskan Way Viaduct closes Jan. 11, 2019, three solid weeks of construction begin. Crews will work around the clock to move State Route 99 off the viaduct and into the new, two-mile SR 99 tunnel beneath downtown Seattle. During the Realign99 closure, the longest highway closure in Seattle’s history, both the viaduct and new tunnel will be closed.

    Why is so much work needed? Today the stretches of SR 99 immediately north and south of the tunnel are temporary road, detours built years ago to keep traffic moving during tunnel construction. On Jan. 11, crews will start removing the detours and completing the ramps to align SR 99 with the new tunnel. The work includes unburying tunnel on-and-off ramps completed in 2014 at the tunnel’s south end. This video explains more:

    While the viaduct closes on Jan. 11, 2019, there will be earlier impacts to traffic. On Jan. 4, the southbound off-ramp at South Atlantic Street will close. Then after the tunnel opens, it will take up to two additional weeks to complete the new northbound off-ramp to Alaskan Way and South Dearborn Street. This is the ramp structure that today stands in the middle of the SR 99 detour just south of the viaduct.

    The Realign99 closure will be a very challenging time for everyone traveling to, from or through Seattle. From past experience we know closing SR 99 makes other highways and Seattle streets more congested. We will need everyone’s help to avoid gridlock. Commuters, employers and travelers – start making your plan, consider changing your habits, follow the conversation on Twitter, and make sure you stay well informed once the closure begins.

    — more —

    Order: 6.6

  • SR 99 closed southbound this weekend for tunnel opening prep work

    Southbound SR 99 will be closed this weekend while crews pour concrete for the future SR 99 roadway coming out of the SR 99 tunnel. Crews will also continue repairing a dip in the highway south of South Atlantic Street. They will move the protected work zone for that repair work from the right side to the left side of the southbound lanes (from the west to the east side of the roadway), keeping two lanes open past the dip repair area.

    This closure allows the contractor to complete weather-dependent work that would otherwise be done during the big Realign99 closure that begins on January 11, 2019. This weekend’s work is partially weather dependent.

    Closure details

    • When: 9:00 p.m. Friday, Nov. 16 – 5 a.m. Monday, Nov. 19
    • What: SR 99 southbound, from the south end of the Battery Street Tunnel to South Spokane Street
    — more —

    Order: 6.7

  • Step Forward: Say “hello” to the new tunnel, “goodbye” to the viaduct, and envision the future of the waterfront

    Before the tunnel opens to drivers, WSDOT and the City of Seattle will host a grand opening celebration Feb. 2 – 3, 2019 to mark the completion of the new SR 99 tunnel, the final days of the viaduct, and an improved and reconnected waterfront.

    The family-friendly event begins Saturday morning with a fun run that takes participants through the new tunnel, onto the viaduct, and through the Battery Street Tunnel. After a ribbon cutting to officially open the new tunnel, activities include:

    • A free walk in the new SR 99 tunnel
    • An art festival featuring over 100 local artists, installations, and a community celebration on the viaduct
    • Community festivals near the SR 99 tunnel’s north and south ends, including food trucks, live music, and science, technology, engineering and math (STEM) activities

    On Sunday morning, the festivities close with a unique bike ride that gives riders their only opportunity to ride on the upper and lower decks of both the tunnel and viaduct in the same day.

    Make a plan and get your tickets

    The weekend’s activities span from the stadiums to the Space Needle, so we encourage participants to visit the Step Forward website to plan ahead. Visit the website to register for the fun run and bike ride and plan your event experience. WSDOT expects a large turnout, so we encourage you to register for free tickets to explore the tunnel and viaduct on Saturday. Those with free tickets will be given entry priority. 

    We look forward to celebrating this exciting milestone!


    — more —

    Order: 6.8

  • Seattle Tunnel Partners reaches first contract milestone

    Close followers of the project know that our website is home to an archive of contractor Seattle Tunnel Partners’ monthly schedule updates. These updates don’t show all the construction that’s happening on the project, but they do give an indication of critical work activities that must be completed to achieve an important contract milestone – “substantial completion” of the tunnel.
    STP reached substantial completion earlier this month. This is the first of three contract milestones in STP’s work on the tunnel. It means the tunnel is far enough along for STP to officially hand the facility over to WSDOT. It doesn’t mean STP’s work is done, but it does mean the tunnel could be technically operated as designed. 
    What comes next is a variety of wrap-up work elements that, once completed, will result in the tunnel reaching the second milestone, known as “physical completion.” Meanwhile, as STP works toward physical completion, WSDOT will continue to train maintenance and operations staff to ensure the tunnel and those responsible for its operation are ready to go in early 2019.
    The final contract milestone, aptly named “final completion,” will be achieved when paperwork and documentation are done. The tunnel will open before this final milestone is reached. You can see the latest schedule update – along with those from previous months – on our schedule page.
    — more —

    Order: 6.9

  • New parking and shuttle options along Alaskan Way

    There are plenty of new parking spaces along the waterfront. WSDOT’s contractor Kiewit is almost finished creating close to 250 parking spaces beneath the Alaskan Way Viaduct.

    Street beneath the viaduct with new parking stripes and traffic cones

    You can reach these spaces via the northbound local-access lane beneath the viaduct. These 4-hour, back-in angle parking spaces will be in place until the contractor begins preparation for removing the viaduct in early 2019. Our Alaskan Way page contains a map of the new street alignment.

    Do you know about the free waterfront shuttle?
    This shuttle van offers free rides between the downtown waterfront and three nearby neighborhoods (Seattle Center, Pioneer Square, and the Central Business District). The shuttle program, extended through summer 2019, is paid for with WSDOT funding set aside to help neighborhoods most impacted by the project.

    What’s ahead for drivers
    The #realign99 highway closure is approaching! We need to close the highway for approximately three weeks in order to complete the ramps connecting the tunnel to SR 99 and local streets. This will be the longest major highway closure the Puget Sound region has ever seen – start making your plan for getting around.

    — more —

    Order: 7.0

  • One more (inspection) for the road: SR 99 closed this weekend for viaduct inspection

    10/17 UPDATE: This weekend's northbound closure has been shortened. Northbound SR 99 will close Saturday, Oct. 20 at 6 a.m. and reopen Saturday afternoon by 5 p.m. The southbound closure remains unchanged.

    This weekend, Oct. 19-22, brings the final scheduled inspection closure of the State Route 99/Alaskan Way Viaduct before the new SR 99 tunnel opens early next year. Both northbound and southbound SR 99 will be closed, including the Battery Street Tunnel.

    Closure Details

    • SR 99 closes southbound at 9 p.m. Friday, Oct. 19 and reopens by 5 a.m. Monday, Oct. 22. The closure is from the north end of the Battery Street Tunnel to South Spokane Street.
    • SR 99 northbound closes at 6 a.m. Saturday, Oct. 20 and reopens by 5 p.m. the same day. This closure is from the north end of the Battery Street Tunnel to South Spokane Street.
    • In addition to a final scheduled inspection, crews will be pouring concrete for the future highway at the SR 99 tunnel’s south portal.

    Since 2001 WSDOT bridge inspectors have been closing the viaduct twice a year to inspect the structure. The 2001 Nisqually earthquake damaged the viaduct, prompting repairs and strengthening, and instigating a rigorous inspection program to make sure the structure remains safe for driving. This weekend will be the 33rd inspection since 2001.

    The viaduct is scheduled to permanently close on Jan. 11th 2019, marking the start of three weeks of intensive roadwork to #realign99 into the new tunnel. WSDOT urges all drivers to make a plan for their commute during the closure, as it will be the longest major highway closure ever in the Seattle area.

    — more —

    Order: 7.1

  • Driver alert: SR 99 closed southbound Oct. 12-15

    10/12 UPDATE: During this weekend’s closure contractor crews will place barrier and barrels on southbound SR 99 just south of the S. Atlantic St exit. This will create a safe work space on the right shoulder (west side) of the highway so crews can pour asphalt and concrete to fix a dip in the highway, and keep it protected while the concrete cures. Later this fall they will move the work zone to the left shoulder (east side) in order to repair the other half of the southbound roadway. These work zones will keep southbound SR 99 to two lanes until approximately S. Holgate Street, where the third lane will open. The southbound dip repair should be complete this fall, weather permitting.

    This weekend Seattle drivers should plan their routes ahead of time as the two main highways through Seattle will have opposite-direction closures. SR 99 will be closed southbound between the south end of the Battery Street Tunnel and South Spokane Street, while I-5 will have northbound lane reductions as part of the Revive I-5 project.

    Closing southbound SR 99 will allow contractor crews to take advantage of good weather to pour concrete near the South Atlantic Street off-ramp. This area, today occupied by the SR 99 detour through the tunnel work zone, will become the merge of southbound SR 99 and the new southbound on-ramp. This work is part of the SR 99 Connections Project, which is completing the eight ramps that will connect SR 99 and the new tunnel to local streets.

    SR 99 closure details:

    • SR 99 southbound closed from south end of Battery Street Tunnel to South Spokane Street
    • Closure begins 9 p.m. Friday, Oct. 12
    • Closure ends 5 a.m. Monday, Oct. 15

    I-5 lane reduction details:

    • Northbound I-5 will be reduced to two lanes between Martin Luther King Jr. Way and Olive Way
    • Lane reductions begin at 8 p.m. Friday, Oct. 12
    • Lane reductions end 5 a.m. Monday, Oct. 15.
    • More details about Revive I-5

    Don't forget: Alaskan Way along the waterfront will be closed Saturday night as crews switch travel lanes west.

    — more —

    Order: 7.3

  • Go west, young road: Alaskan Way shifts west this weekend

    This weekend Alaskan Way will move west, out from beneath the Alaskan Way Viaduct. The new alignment will feature two lanes in each direction from King Street to Union Street. Moving the travel lanes west will allow us to keep the street open when viaduct removal work begins in early 2019.

    Alaskan Way will be closed this weekend from 8 p.m. Saturday, Oct. 13 to 10 a.m. Sunday, Oct. 14. During the closure, Western Avenue will be the primary detour route. Access to Colman Dock will be maintained via South Jackson Street (entrance) and Yesler Way and Marion Street (exits).

    This map below shows the new street alignment. Construction and utility work for the rebuilding of Pier 62 will constrain Alaskan Way to one lane in each direction near the Aquarium (from Union Street to Pine Street) until the end of November.

    Map of Alaskan Way along waterfront showing two lanes in each direction

    Click on image to see larger version of map

    The space under the viaduct previously occupied by Alaskan Way’s travel lanes will be restored to hold a northbound business access lane and temporary new parking spaces. These spaces, which will add at least 70 additional parking stalls above the number removed for the switch, are scheduled to be completed by the end of October. Those spaces will be in place until the area is needed for viaduct removal construction work in early 2019.

    — more —

    Order: 7.2

  • Emergency response exercise in the tunnel this Thursday

    An emergency response drill this Thursday will bring a new dimension to the ongoing testing of the SR 99 tunnel's many interconnected systems. This full-scale exercise will give the agencies involved in responding to tunnel events or emergencies a chance to practice in the tunnel. 

    The exercise will involve staged crashes, actors playing injured travelers, emergency response crews, and activation of the tunnel's deluge fire suppression system. Most of the activity will take place inside the tunnel, but people near the tunnel's north portal might see vehicles or drill participants. Representatives from WSDOT, SDOT, the Seattle Police and Fire Departments, King County Metro Transit and the federal Transportation Security Administration will be involved.

    The tunnel is set to open in early 2019 after tunnel testing and commissioning is complete and crews build the ramp and roadway connections at both ends of the tunnel. The final burst of work on those ramp and roadway connections will begin with the start of the #realign99 closure, scheduled to begin January 11, 2019.

    — more —

    Order: 7.4

  • 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.

    — more —

    Order: 7.5

  • 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). Oct. 10 update: updated map to newer 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 DowntownSeattleParking.com.

    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 WaterfrontConstruction.org.


    — more —

    Order: 7.6

  • 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 www.99tunnel.com.

    — more —

    Order: 7.7

  • 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.

    — more —

    Order: 7.8

  • 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.

    — more —

    Order: 7.9

  • Trimming the tunnel with lane stripes and stick figures

    Scientists are still trying to figure out how the zebra got its stripes. In the case of the SR 99 tunnel’s stripes, there is no mystery. This past weekend, crews working for Seattle Tunnel Partners finished striping the tunnel between the stadiums and the Space Needle.
    View from above of tunnel portal showing roadway with yellow and white lane stripes
    The stripes separate each of the tunnel’s roadway decks into two 11-foot lanes, an 8-foot shoulder on the left side and a two-foot buffer on the right.   
    Tunnel interior showing yellow and white striping for two lanes and wide shoulder
    Meanwhile, work on another kind of paint job is underway inside the tunnel. Crews are using stencils to paint tall, running stick figures on walls in both directions of the tunnel. 
    Tunnel interior with blue stencil of exit sign on right wall
    The green icons are spaced about 50 feet apart on the west walls of the southbound (upper) and northbound (lower) roadways. As shown in the photo, arrows point the way to the nearest exits, along with the distances to them. 
    Tunnel interior showing green exit sign with running stick figures painted on right wall
    If the seven-foot-tall green stick figures don’t get your attention, flashing lights at each of the tunnel’s emergency exits and electronic signs will provide additional guidance. 
    The tunnel could open as soon as this fall, after an approximately three-week viaduct closure to realign SR 99 into the new tunnel. Keep following our website and Twitter account for more information as we move closer to opening the tunnel and taking down the viaduct.
    — more —

    Order: 8.0

  • 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 99. Keep 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.


    — more —

    Order: 8.1

  • 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.

    — more —

    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.
    — more —
  • 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.

    — more —

    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 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.

    — more —

    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.

    — more —
  • 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.

    — more —

    Order: 8.6

  • 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.

    — more —

    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.

    — more —

    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.

    — more —

    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.

    — more —

    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
    — more —
  • 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.

    — more —

    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.

    — more —

    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.

    — more —

    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

    — more —

    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.

    — more —

    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.

    — more —

    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.

    — more —

    Order: 9.9