Advisories and Updates 2016

2016 Program News

  • Dec. 21 project update: Bertha and crew begin holiday break

    Seattle Tunnel Partners crews built their final concrete tunnel ring of the year on Tuesday before stopping for the holidays. The remaining days of 2016 will include a break for crews, followed by scheduled maintenance on Bertha, the SR 99 tunneling the machine.
     
    In the year since STP restarted tunneling, Bertha has traveled approximately 5,700 feet and built almost 900 rings. Along the way, crews continued to control the ground as they mined beneath streets and structures, including the Alaskan Way Viaduct.
     
    When mining resumes early in the new year, Bertha will be less than 2,500 feet from the pit near Seattle Center where she’ll emerge at the end of her journey. STP will continue to inspect and perform maintenance on the machine as needed.
     
    Bertha’s cutterhead is located approximately 160 feet below Third Avenue between Blanchard and Bell streets. Progress updates are posted on Mondays and Thursdays at our Follow Bertha page. You can also follow Bertha on Twitter @BerthaDigsSR99
     
    Happy holidays from the Alaskan Way Viaduct Replacement Program. We’ll see you in 2017.
     
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  • Dec. 16 project update: Get ready for the year of the north portal

    As we get set to flip the calendar, there’s no doubt about it: 2017 will be a big year at the north portal.

    Yes, Bertha is scheduled to arrive here in June 2017, but there’s much to look forward to before that day comes. In fact, some important changes could take place before the start of the new year.

    Several new street connections are set to open soon near the future north portal operations building. The opening of these new roadways, as well as additional sidewalks in the area, will increase mobility and create new connections to nearby city streets.

    The extension of Sixth Avenue North between Harrison and Mercer streets is slated to open in late December. Harrison Street, between Taylor Avenue North and SR 99/Aurora Avenue North, will open shortly after. Only right turns will be permitted to and from southbound SR 99 at Harrison Street. Details are shown in the map below.  

    These new connections are among the final steps in our North Access Project, which built new roadway connections to the future tunnel. Contractor Atkinson Construction will be wrapping up work over the next few weeks.

    Traffic changes map for 6th Ave at the north portal

    This map shows traffic changes that will be happening soon near the tunnel's north portal.

    A polished look
    Much of the permanent landscaping at the north portal has been installed. That includes the “signature tree” that crews planted earlier this year. Additionally, Seattle Tunnel Partners crews are building a new plaza outside the north portal operations building. Read more about the plaza in our new Program Spotlight.
     
    Getting ready for Bertha
    Bertha has approximately 2,600 feet to go in her tunneling journey. She’ll reach daylight here, in a large pit just north of Thomas Street, near the operations building. STP will then shift its focus to removing the massive machine in pieces from the pit as they continue building the double-deck highway inside the tunnel.
     
    New connections
    Today, John, Thomas and Harrison streets are divided by traffic traveling on Aurora Avenue North. When the viaduct program is complete, these streets will connect across Aurora. This change is possible because SR 99 traffic will enter the new tunnel further north than it does in the current highway configuration. The Harrison Street connection across Aurora will open when the tunnel does; John and Thomas streets will be reconnected by a future contractor. Increasing the number of east-west connections will improve mobility in the neighborhood.
     
    Street connections at the north porta

    This map shows the reconnected street grid near the north portal at the end of the program.
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  • Dec. 15 project update: Operations buildings nearly complete

    As Bertha continues mining toward the north portal, crews are nearing completion on what will ultimately be the most recognizable features of the SR 99 tunnel: the operations buildings at each portal. If you’ve driven on SR 99 through Seattle, you’ve seen them – who could miss the bright yellow ventilation stacks?
     
    The stacks are central to the tunnel’s ventilation system, which will be capable of removing 1.4 million cubic feet of air per minute should it be necessary. In addition to ventilation, the buildings will house operating systems, including safety, lighting and communications. They’ll also provide space and access for the very thing that inspired the colorful stacks – WSDOT’s yellow maintenance vehicles. 
     
    Both buildings will be mostly complete by next year, although a portion of the north operations building will be completed after the tunneling machine is removed from the ground. Crews have installed the stacks and main ventilation fans, as well as all exterior glass, in both buildings. The focus now is on completing the remaining interior work. 
     
    Permanent power was recently connected to the north operations building, which is located at the corner of Harrison Street and Sixth Avenue North. The building’s interior, as well as the plaza that’s taking shape outside, are now lit up at night.
     
    The south operations building, which is located on the south side of South King Street, will be connected to the electrical grid in 2017.  
     
    Both buildings were designed to be beacons of light rather than blocks of cold concrete. The ventilation rooms of both operations buildings will stay lit throughout the night, acting as luminous bookends to the bored tunnel.
     
    North operations building
     
    North plaza
    The plaza outside the north operations building takes shape.
     
    North roof
    Looking north from the roof of the north operations building.
     
    South operations building 
     
    South operations interior
    A look inside the south operations building.
     
    South building exterior
    The glassy exterior of the south operations building is visible beyond stacks of tunnel segments. 
     
    ***
    It's been nearly one year since the SR 99 tunneling machine resumed mining following the tunneling delay. We're highlighting a different aspect of the program each day this week to illustrate the progress we've made to date. Yesterday’s post highlighted #BalloonsOverBertha, one of many ways to track progress.

     

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  • Dec. 15 project update: Looking ahead to 2017 and beyond

    Day by day, ring by ring, the SR 99 tunnel continues to take shape beneath downtown Seattle. The tunnel now stretches from its starting point near the stadiums to the ground beneath Belltown, more than a mile to the north. As we’ve been highlighting throughout the week, construction is progressing at the north and south portals, and inside the tunnel, where crews are building the future double-deck highway that will carry traffic on SR 99. 
     
    In July, as part of our semiannual update to the Legislature’s Joint Transportation Committee, we reported that the tunneling delay had led to additional WSDOT costs for longer-than-expected contract administration and oversight, as well as the need to extend agreements and leases with property owners above and near the tunnel route. We estimated this provisional need at $223 million over the remaining life of the program, but said we needed time to further refine our budget request prior to the upcoming legislative session.  
     
    Today, we presented that update to the committee. The current legislatively approved budget for the program is $3.1 billion. Our revised estimate shows an additional budget need of $149 million – $74 million less than what we anticipated in July. Of that, $60 million will be needed in the upcoming 2017-2019 biennium to continue supporting our work to replace the Alaskan Way Viaduct. A copy of the full presentation is available on the JTC’s website.
     
    Why is our budget request $74 million less than our July estimate? Simply put, we now have more information. In preparation for this budget request, we spent the past five months thoroughly reviewing every project schedule and every facet of our program. That included looking for new efficiencies, performing a statistical risk analysis and updating our cost estimates.  
     
    As part of our process to refine these estimates, we set aside contingency funding. We did this by identifying remaining risks and calculating the potential costs associated with those risks, should they materialize. The biggest remaining risk – tunnel mining – is slated for completion next spring. We will continue to closely manage this and other risks moving forward.   
     
    It’s important to note that none of these additional funds will be used to pay for tunneling machine repairs. This funding request is strictly to cover other program costs that were incurred because of the tunneling delay. We will continue to follow the tunnel project’s design-build contract to recover the added expense. This includes pursuing insurance claims, identifying potential cost savings in other elements of the program and ongoing litigation to recover damages. If efforts to recover costs are successful, the funds would likely not be available until after the project is complete.
     
    Our goal, in everything we do, is to deliver critical projects while also protecting taxpayers. Replacing the viaduct is a massive endeavor consisting of 32 separate but related projects. Twenty-one of those projects are now complete, and the biggest one – the SR 99 tunnel – is on the path to successful completion. 
     
    Next year will bring the breakthrough of the SR 99 tunneling machine. We look forward to that milestone, and to fulfilling the mission we began at the outset of this program: removing the viaduct and setting the stage for Seattle’s new downtown waterfront.
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    Order: 1.3

  • Dec. 14 project update: Another way to track Bertha’s progress

    This afternoon, we shared the latest edition of #BalloonsOverBertha via our Twitter account. Launched in late August when Bertha passed beneath First Avenue and Union Street, #BalloonsOverBertha is yet another way to track progress on the SR 99 Tunnel Project. 
     
    The idea is to provide a visual of Bertha’s location relative to the surface. Generally, we’ll share a new balloons photo each time Bertha passes beneath a street. Today’s photo highlights Bertha’s passage beneath the intersection of Third Avenue and Blanchard Street. We’ll also occasionally share a balloons photo when something of local interest is happening, such as major sporting or community events.
     
    We only put the balloons out long enough to take a photograph, so please don’t make a special trip to see them in person. The best view is on Twitter at #BalloonsOverBertha. You can follow Bertha on Twitter @BerthaDigsSR99. We also post twice-weekly progress updates on our Follow Bertha page. As of Tuesday, the machine had traveled 6,555 of 9,270 feet and installed 1,000 of 1,426 concrete tunnel rings.
     
    Balloons over Bertha at Blanchard Street
    #BalloonsOverBertha at Third Avenue and Blanchard Street.
     
    ***
     
    It's been nearly one year since the SR 99 tunneling machine resumed mining following the tunneling delay. We're highlighting a different aspect of the program each day this week to illustrate the progress we've made to date. Yesterday’s post highlighted work inside the tunnel.
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    Order: 1.3

  • Dec. 13 project update: Crews install the tunnel's 1,000th ring

    Today was just an ordinary Tuesday morning 170 feet beneath Belltown, where crews building the SR 99 tunnel continue their subterranean push toward the north portal.
     
    Build a concrete tunnel ring, dig forward. Build another ring, dig forward. It’s a task the ring-building crews working on Bertha, the SR 99 tunneling machine, will perform 1,426 times over the course of the project. As you might expect, they become more efficient with each ring they build.
     
    “We’re in a really good rhythm,” said ring-builder Cody Heck, in our newest video, posted below. “I think my first ring that I built here was about an hour and a half. Now it’s down to about 40 minutes.”
     
    Over time, of course, the rings add up. Which brings us back to Tuesday morning, when crews installed the tunnel’s 1,000th ring. With Bertha’s cutterhead approaching the ground beneath Third Avenue and Blanchard Street, tunnel boring is now 70 percent complete.
     
    What will crews do now that they’ve reached 1,000 rings? Build more rings, of course. Heck explains the process below.
     
     
    Highway construction progress
    Ring-building is only one component of SR 99 tunnel construction. A separate crew is hard at work behind the tunneling machine, building the double-deck highway that will carry traffic when the tunnel opens.
     
    Construction of the highway occurs in 54-foot sections. Crews build each section in stages. The time-lapse video below shows the process in 60 seconds. 
     
     

    As you can see in the video, multiple sections of the highway are under construction at any given time. The graphic below shows the different stages.

    SR 99 tunnel highway construction steps

    Building the highway in this fashion allows concrete the time it needs to strengthen before additional components of the highway are added at a given section. It also allows workers to spread out and complete the portion they’re working on more quickly than would be possible if all crews were focused on the same area at the same time. 
     
    As shown in this Dec. 9 report, wall foundations now extend past Pike Street. The tunnel’s walls now reach to Union Street. The southbound roadway deck has been completed to approximately Spring Street. Moving forward, we’ll be posting these reports every Friday on the Follow Bertha page.
     
    ***
    It's been nearly one year since the SR 99 tunneling machine resumed mining following the tunneling delay. We're highlighting a different aspect of the program each day this week to illustrate the progress we've made to date. Yesterday’s post highlighted work at the tunnel’s future south portal.

     

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    Order: 1.4

  • Dec. 12 project update: The south portal comes into focus

    It's been nearly one year since the SR 99 tunneling machine resumed mining following the tunneling delay. We'll be highlighting a different aspect of the program each day this week to illustrate the progress we've made to date.

    It all began in the south end. Before Bertha, before cut-and-cover tunnels and new ramps and temporary lanes, the land to the west of the stadiums belonged to the viaduct's southern mile.

    A time traveler from 2008 would barely recognize the landscape that's now home to the SR 99 tunnel's south portal. Back then, in addition to the viaduct, the area was home to warehouses and large swaths of pavement. Freight heading to and from nearby Terminal 46 was frequently blocked by trains.

    Photos of south portal location
     

    Today, the south portal is a much different place. The south end of the viaduct has been demolished and replaced, and a new overpass has created an uninterrupted connection for freight. A temporary section of highway carries SR 99 traffic around the tunnel work zone.

    The land where the viaduct once stood is now bustling with construction activity. Crews have built hundreds of feet of cut-and-cover tunnel through this area, and the future entrances and exits into and out of the tunnel are visible at the surface. It's now possible to walk from the start of the cut-and-cover section of tunnel near South Royal Brougham Way all the way to the ground beneath Third Avenue and Blanchard Street – a distance of nearly a mile and a half!

    Drivers on SR 99 are now treated to views of the south portal operations building's glassy exterior, along with its signature yellow ventilation stacks. This building, along with a similar building at the north portal, will house the tunnel's lighting, ventilation and emergency systems when it opens to traffic.

    The south portal work zone continues to be the main hub for tunnel construction. It's where materials are stored, including the curved concrete segments that make up the tunnel walls which crews lower into the launch pit using a large crane. From there, a special vehicle drives them to the tunneling machine for installation.

    West of the main work zone, on a portion of the Port of Seattle's Terminal 46, crews load excavated soil onto a barge that takes the soil to a disposal site in Port Ludlow. The soil makes its way to the barge via a conveyor system that grows as the tunneling machine moves forward. More than one million tons of soil have been removed from the tunnel so far.

    New bridge technology

    As part of a separate contract, crews working for Interwest Construction are building the future northbound off-ramp to South Dearborn Street. But this isn't just any off-ramp.

    By combining memory-retaining metal rods and a bendable concrete composite, the future off-ramp will become the first bridge in the world built to sway with a strong earthquake and return to its original shape.

    The video we released last month explains how this exciting new technology works.

    What's next at the south portal?

    Construction at the south portal won't slow down anytime soon. Future contracts will be responsible for building the final highway and ramp connections that will allow us to open the tunnel to traffic. Until then, we're working hard to turn the rendering below into reality.

    Rendering showing what is next at the south portal

     

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    Order: 1.5

  • Nov. 21 project update: Bertha nearing the tunnel’s deepest point

    Seattle Tunnel Partners passed the 60 percent mark of tunnel boring last week. As of this morning, crews had mined 5,774 of 9,270 feet and installed 880 of 1,426 concrete tunnel rings. 
     
    Bertha, the SR 99 tunneling machine, is located near Virginia Street, between First and Second avenues. With the top of the cutterhead now approximately 210 feet below the surface, crews are nearing the deepest point of the tunnel drive. 
     
    STP will continue mining and other construction activities through Wednesday before securing the work zone for the holiday weekend. Work will resume on Monday.
     
    Happy Thanksgiving from the Alaskan Way Viaduct Replacement Program team.
     
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    Order: 1.2

  • Nov. 7 project update: Girders arrive for future off-ramp

    Large bridge girders began arriving Monday in the work zone near the stadiums. Crews will install the girders this week on the new bridge that will serve as the off-ramp from northbound SR 99 to South Dearborn Street after the tunnel opens to traffic.
     
    The bridge will include 14 girders in all. The four largest girders will be installed overnight Tuesday, requiring crews to close the left lane of northbound SR 99 between South Holgate Street and Railroad Way South from 9 p.m. Tuesday to 5 a.m. Wednesday.
     
    You can see regularly updated images of the girder installation on our south-end construction cameras.
     
    Off-ramp girders
    Crews are installing bridge girders near the stadiums as part of the South Dearborn Street Off-ramp Bridge Project. This post explains how this "flexible" bridge will use new technology to stand up to earthquakes. This folio provides a detailed technical description of the materials being used.
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  • Nov. 3 project update: Bertha passes the one-mile mark

    Seattle Tunnel Partners passed the 5,280-foot mark of the SR 99 tunnel on Thursday morning. Less than 4,000 feet now separates the front end of Bertha, the SR 99 tunneling machine, from the receiving pit (links to YouTube) near the Space Needle where Bertha will emerge at the end of tunneling. Bertha’s cutterhead is located more than 200 feet below First Avenue, just north of Stewart Street.
     
    The one-mile point in Bertha’s journey also marks the tunnel route’s departure from the ground beneath First Avenue. While First veers northwest at Stewart Street, Bertha will continue pushing north toward the receiving pit. By passing Stewart Street, Bertha entered Zone 7 of the tunnel drive
     
    How do crews steer the five-story-tall tunneling machine toward the finish line some 4,000 feet to the north? We asked Jerry Roberge, one of Bertha’s operators, that very question. Jerry’s answer, along with exclusive footage from inside the tunnel, can be seen in the video below.
     
     
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  • Oct. 31 project update: Bertha resumes mining

    Seattle Tunnel Partners resumed mining Monday following a week of tunneling machine maintenance. Crews working in hyperbaric conditions changed approximately 100 cutterhead tools during the maintenance stop, which began on Oct. 22.
     
    The machine has more than 700 cutterhead tools in all, but crews only inspect and replace a portion of them each time they stop for maintenance. This post explains more about the different types of tools and the methods crews use to replace them.
     
    Bertha, the SR 99 tunneling machine, is more than 200 feet beneath First Avenue, approaching Stewart Street. Before mining started Monday morning, crews had mined 5,085 feet and installed 774 concrete tunnel rings.  
     
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  • Oct. 24 project update: Bertha passes the 5,000-foot mark

    Seattle Tunnel Partners passed the 5,000-foot mark of the SR 99 tunnel drive late last week. Crews have mined 5,085 feet of the 9,270-foot-long tunnel and built 774 concrete rings. Bertha, the SR 99 tunneling machine, is now located below First Avenue, just north of Pine Street.

    STP is currently performing routine hyperbaric maintenance on the machine, including the inspection and replacement of cutterhead tools (this post explains more about the different methods for changing tools). Previous hyperbaric stops have lasted as long as seven weeks. However, STP has indicated they may choose to do shorter and more frequent hyperbaric stops moving forward.

    Now more than 200 feet below the surface, crews are approaching the deepest point in the tunnel drive. A map and description of the tunnel route – as well as twice weekly progress updates – are available on our Follow Bertha page. You can also follow Bertha on Twitter @BerthaDigsSR99

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  • Oct. 12 project update: After a brief checkup, Bertha is back on the move

    Seattle Tunnel Partners resumed mining on Tuesday following a week of planned maintenance on Bertha, the SR 99 tunneling machine. During the stop, crews performed routine maintenance, including the inspection of cutterhead tools.
     
    Crews initially expected to spend several weeks changing tools in hyperbaric conditions. However, after a full day of hyperbaric work and tool inspection on Monday, STP determined the cutterhead tools were in satisfactory condition and decided to continue mining.  
     
    With the machine functioning well and the cutterhead tools in good condition, STP will continue mining north beneath First Avenue. They plan to make at least one more stop to perform hyperbaric work, but the timing and location of future stops will be determined by STP based on soil conditions and maintenance needs. 
     
    The top of the tunneling machine is located nearly 200 feet below First Avenue, approaching Pine Street. As of this morning, crews had tunneled 4,750 feet of the 9,270-foot-long tunnel drive. Progress updates are posted on Mondays and Thursdays at our Follow Bertha page. You can also follow Bertha on Twitter @BerthaDigsSR99.
     
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  • 5:00 p.m. Sat Update: Viaduct inspection complete and is now open

    Crews have completed the semiannual inspection of the Alaskan Way Viaduct and the viaduct is now open to traffic. It will no longer be closed on Sunday as had been anticipated.

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  • Oct. 6 project update: Bertha reaches planned maintenance stop

    Seattle Tunnel Partners has paused mining to begin planned maintenance on Bertha, the SR 99 tunneling machine. Crews stopped tunneling approximately 190 feet beneath First Avenue, just north of Pike Street, on Tuesday, Oct. 4. STP chose the location of the stop in advance because dense soils in the area are suitable for hyperbaric work – a process this post explains in detail.
     
    Crews will spend several days preparing the hyperbaric work environment. They will then begin the difficult task of inspecting and changing cutterhead tools. There are more than 700 tools on Bertha’s rotating cutterhead, some of which can be accessed and changed from within the cutterhead spokes during the course of STP’s regular weekend maintenance. The cutting tools that crews will focus on during the upcoming maintenance period can only be accessed in hyperbaric conditions. 
     
    Replacing cutting tools and performing other maintenance is crucial to maintaining the tunneling machine and ensuring it performs well for the remainder of the tunnel drive. This is STP’s third planned maintenance stop in 2016. The machine was stopped from March 12 to April 29 as crews prepared to tunnel beneath the Alaskan Way Viaduct. A second maintenance stop occurred beneath Spring Street from June 23 to July 18. STP expects the current maintenance period to last approximately one month, but the length of the stop will depend on the extent of the needed work.
     
    Crews have mined a total of 4,721 feet and installed 717 concrete rings since tunneling began. They are now more than halfway through the tunnel drive. We’ll continue to provide updates on hyperbaric work and other progress around the viaduct program as STP’s machine maintenance continues.
     

     

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  • Alaskan Way Viaduct to close the weekend of Oct. 8 and 9

    From 6 a.m. to 6 p.m. Saturday, Oct. 8, and Sunday, Oct. 9, both directions of SR 99 will be closed between South Spokane Street and the north end of the Battery Street Tunnel for a semiannual inspection. WSDOT closes the viaduct for inspection every fall and spring so WSDOT engineers can thoroughly examine the aging roadway and make sure it remains safe for drivers.

    Also, between 6 a.m. and 3 p.m. Saturday, Oct. 8 only, crews working north of the Battery Street Tunnel will close SR 99 in both directions from the tunnel to Valley Street. Northbound drivers can access SR 99 at Valley Street.   

    Fall 2016 Alaskan Way Viaduct semiannual inspection closure map

    Fall 2016 Alaskan Way Viaduct inspection closure map

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  • Oct. 3 project update: Bertha pushes past halfway point in SR 99 tunnel dig

    The SR 99 tunneling machine Bertha has passed a significant milestone in its journey underneath Seattle. When the machine tunneled past Pike Place Market on Friday, Sept. 30, it pushed beyond the halfway mark of a 9,270-foot-tunnel that will lead to the removal of the Alaskan Way Viaduct.

    Seattle Tunnel Partners has now excavated more than 4,635 feet of the SR 99 tunnel. Much of that progress occurred during the past five months, with STP tunneling more than 3,000 feet since leaving a planned maintenance stop on April 29 to begin the push beneath the viaduct.

    Bertha is now about 190 feet beneath First Avenue between Pike and Pine streets. According to STP, crews will continue mining for a short time and then stop to perform approximately one month of planned maintenance.

    The finish line – a 90-foot-deep receiving pit near Thomas Street, at the north end of downtown – is largely complete, along with many other aspects of the tunnel portals. Although future contractors will make final connections to the highway, several of the ramps and roadways into and out of the tunnel are already in place, along with tunnel operations buildings at each of the portals. New drone footage of Bertha’s finish line is now available.

    Other important work is ongoing, including construction of the double-deck highway within the tunnel.

    While STP’s crews are making progress, they are also taking time for routine maintenance to help ensure the machine successfully completes the tunnel drive. Like previous maintenance stops, crews will use the upcoming stop to inspect machine components and replace cutterhead tools in hyperbaric conditions. STP expects this round of maintenance to last approximately one month, but it could take more or less time depending on the extent of work needed.

    STP’s most recent schedule shows that tunneling will wrap up in summer 2017. Work to complete the tunnel’s interior structures, along with installing and testing systems should be finished by late 2018. Based on STP’s schedule, WSDOT estimates the tunnel would open to traffic in early 2019 when crews finish connecting the tunnel to the existing SR 99 roadways.

    Recent tunneling updates 
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  • Sept. 12 project update: Bertha back on the move

    Seattle Tunnel Partners resumed mining today following a temporary stop to change tools on the cutterhead of Bertha, the SR 99 tunneling machine. As of lunchtime, crews were tunneling north approximately 170 feet below First Avenue, just north of Union Street.
     
    Crews replaced a total of 14 large cutting tools during the two-week maintenance period. Bertha has moved from clay to a mixture of sand and gravel that wears down cutting tools more quickly. A photo comparing a new cutting tool with a worn cutting tool is available in this post.
     
    The tools STP changed during this maintenance stop are the first parts of the cutterhead that contact the ground, making them crucial to the machine’s ability to excavate soil. STP will continue to inspect and replace these tools as needed during the course of mining. They are also planning Bertha’s next hyperbaric maintenance stop, the location of which is still being determined.
     
    The machine has tunneled more than 4,135 feet and is nearing the halfway point of its 9,270-foot-long journey. The entire tunnel route, including descriptions of each of the 10 zones through which Bertha is mining, can be found on our Follow Bertha page. Tunneling statistics are updated on that page on Mondays and Thursdays. You can also track Bertha’s progress on Twitter @BerthaDigsSR99.
     

     

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  • Sept. 8 project update: Cutterhead maintenance continues

    Seattle Tunnel Partners is continuing to change large cutting tools on the cutterhead of Bertha, the SR 99 tunneling machine. Crews have inspected 12 tools – replacing 10 of them – during the current maintenance stop. They could change up to four additional tools before they resume mining. 
     
    This is a normal part of tunnel mining. Cutting tools wear down over time and must be replaced regularly. Bertha recently transitioned from soft clay to a more abrasive mixture of sand and gravel, resulting in greater tool wear. 
     
    The tools STP is focused on during this maintenance stop are the first parts of the cutterhead that contact the ground, making them crucial to the machine’s ability to excavate soil. Replacing them now will preserve the cutterhead and keep the machine in good working order as it continues mining north beneath downtown.
     
    The current maintenance does not require crews to work in hyperbaric conditions, as they did during the previous two maintenance stops. That’s because the cutting tools along the spokes of the cutterhead can be accessed from within the machine, at regular air pressure. Crews performing the work must climb into tight quarters inside the spokes and use hoists and chains to remove the tools, which weigh up to 600 pounds. 
     
    STP will resume mining when the tool replacement is complete, no sooner than next week. We’ll continue to provide updates as this work progresses.
     

     

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  • Aug. 31 project update: New soils, new tools for Bertha

    After tunneling more than 1,000 feet since their last maintenance stop, Seattle Tunnel Partners has paused to inspect and replace some of the larger cutterhead tools on the front end of Bertha, the SR 99 tunneling machine. STP chose to check the tools – and change them as needed – because Bertha has moved from clay into a mixture of sand and gravel that will more quickly wear them down. Replacing the tools now will preserve the machine and ensure it continues to function well as it mines toward STP’s next planned maintenance stop. 
     
    This work does not require crews to work in hyperbaric conditions as they did during the previous two maintenance stops. Still, their task is challenging. Crews must climb into tight quarters inside the spokes of the cutterhead and remove tools weighing up to 600 pounds with hoists and chains. Each tool can take 20 or more hours to remove, inspect and reinstall. 
     
    Crews have inspected four tools since they stopped mining late last week, and they could inspect up to eight more in the coming days. STP will resume mining when tool replacement is complete, no sooner than next week.
     
    The cutterhead is approximately 170 feet beneath First Avenue, near Union Street. The entire tunnel route, including descriptions of each of the 10 zones through which Bertha is mining, can be found on our Follow Bertha page. Tunneling statistics are updated on that page on Mondays and Thursdays. You can also track Bertha’s progress on Twitter @BerthaDigsSR99.
     
    Cutting tools
     
     

     

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  • Aug. 22 project update: Bertha passes the 4,000-foot mark

    Seattle Tunnel Partners crews have now mined more than 4,000 feet as they continue their push toward the SR 99 tunnel’s future north portal. As of this morning, Bertha, the SR 99 tunneling machine, had traveled approximately 4,000 feet of the 9,270-foot-long tunnel route, and installed 607 of the concrete rings that form the tunnel’s exterior walls. 
     
    The top of the cutterhead is approximately 165 feet below the centerline of First Avenue, approaching Union Street. Crews will continue mining beneath First Avenue for several blocks. Then, at Stewart Street, where First Avenue veers to the west, tunneling crews will continue mining north en route to the spot near Seattle Center where Bertha will emerge
     
    As we’ve highlighted before (links to YouTube), the program has an extensive network of instruments in place to monitor ground movement. Crews continue to see little to no movement as they tunnel through a mixture of clay, sand and gravel beneath downtown.
     
    The entire tunnel route, including descriptions of each of the 10 zones through which Bertha is mining, can be found on our Follow Bertha page. Tunneling statistics are updated on that page on Mondays and Thursdays. You can also track Bertha’s progress on Twitter @BerthaDigsSR99.
     
    The SR 99 tunnel under First Avenue in Seattle
    A look at the SR 99 tunnel as it curves toward First Avenue. Other recent project photos can be seen here.
     

     

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  • Aug. 4 project update: New video highlights tunnel segments as Bertha nears First Avenue

    Bertha, the SR 99 tunneling machine, is approaching the intersection of First Avenue and University Street as crews with Seattle Tunnel Partners continue mining north beneath downtown.
     
    As of this morning, the tunneling machine had traveled a total of 3,518 feet and installed 533 concrete tunnel rings. The top of the machine is nearly 130 feet below street level. Earlier this week, crews successfully tunneled beneath the off-ramp that connects northbound SR 99 to Seneca Street. The machine passed approximately 90 feet below the the piles that support the ramp.
     
    Crews will continue tunneling north beneath First Avenue for several blocks. Their ultimate destination is a receiving pit near Seattle Center, where Bertha will end her 9,270-foot-long journey beneath downtown.
     
    The building blocks of the SR 99 tunnel
    Crews have now installed more than 5,000 curved concrete segments in the tunnel – each one weighing an average of 36,000 pounds. Bertha takes 10 of these segments and creates a five-story-tall tunnel ring, as shown below. 
     

    Steps of ring building

    A look at how each tunnel ring is pieced together by Bertha, the SR 99 tunneling machine.

    It will take 1,426 of these rings – or 14,260 concrete segments – to create the nearly two-mile-long tunnel. All the precast segments were built locally, at the Encon Washington plant in Pierce County. Segment production wrapped up in fall 2014. Every segment is checked multiple times for quality before being brought into the tunnel for installation. This video shows you exactly what the tunnel is made of – building blocks of steel and concrete.
     
     
     

     

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  • Crews break ground on new off-ramp at the tunnel’s south portal

    South-end travelers will soon see their future access point from northbound SR 99 to downtown Seattle and SODO take shape near the stadiums. 
     
    Crews from Interwest Construction broke ground this week on a new bridge that will connect northbound SR 99 to South Dearborn Street when the SR 99 tunnel opens to traffic. Construction of the $3.56 million ramp is expected to last approximately nine months. 
     
    This work won't significantly affect the public because it will take place inside the existing south portal work zone, although it will require a few overnight closures on SR 99. We will keep the public informed as work progresses.
     
    South Dearborn Street Off-ramp Bridge   
    The above rendering shows the future off-ramp from northbound SR 99 to South Dearborn Street, near the stadiums. Crews from Interwest Construction broke ground on the new ramp this week (below).
     
     
    Ramp construction begins
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  • Aug. 1 project update: Bertha enters Zone 5

    Seattle Tunnel Partners mined into Zone 5 of the tunnel drive late last week. Bertha, the SR 99 tunneling machine, has now traveled approximately 3,400 feet and installed 515 concrete tunnel rings. The completed bored tunnel will be 9,270 feet long, and will be made up of 1,426 rings.
     
    The top of the machine is nearly 130 feet below Seneca Street, just west of First Avenue. By the time crews reach University Street – one block to the north – they will be tunneling beneath First Avenue.
     
    Progress updates are posted each Monday and Thursday on our Follow Bertha page. You can also track tunneling progress on Twitter @BerthaDigsSR99.
     
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    Order: 1.2

  • Construction highlights for Friday, July 22 - Friday, July 29

    North end

    Started Wednesday, July 20 for approximately two weeks
    • One lane of southbound SR 99 will be closed intermittently at the three locations of Raye, Valley and Comstock streets from 7 p.m. to 6 a.m. Monday through Thursday nights.
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  • July 21 project update: The path to program completion

    The first half of 2016 has seen exceptional progress on the SR 99 Tunnel Project. Since tunneling resumed in late December of 2015, Seattle Tunnel Partners crews have mined an additional 2,100 feet. One-third of the tunnel is constructed, and crews inside the tunnel are hard at work building the future highway. Progress is also visible at the north and south portals, where the tunnel operations buildings, and many of the future ramp and highway connections, are nearing completion.

    WSDOT’s focus is on delivering the entire Alaskan Way Viaduct Replacement Program, comprised of 31 projects. It has been nearly a decade since we broke ground on our first project. Since then, we have successfully completed 21 of those projects, and half of the viaduct has been demolished and replaced. 

    At the north portal, Atkinson Construction is in the final stages of the North Access Project, which is building the highway connections to the tunnel near the Space Needle.

    At the south portal, crews from Interwest Construction are preparing to start work on a newly-awarded contract to build a bridge near the stadiums that will serve as the northbound exit from SR 99 after the tunnel opens to traffic.

    Moving forward

    We are on the path to completion. After resuming tunneling, STP updated their schedule, allowing us to do a preliminary review of the overall program schedule and budget.

    As anyone who follows our work is aware, the tunnel project is delayed, which has led to additional WSDOT costs. For example, there are costs for contract administration and oversight. The costs to acquire right of way along the tunnel alignment have also been higher than originally projected, in part because of the need to extend agreements and leases. Upcoming construction projects, such as demolishing the viaduct, will have additional costs due to the tunneling delay.

    The legislatively-approved budget for the program is $3.1 billion. Based on our preliminary review, what we anticipate today is a 1.8 percent budget increase, or a cash-flow need of up to $60 million in the 2017-2019 biennium, to ensure continued progress.

    Looking toward completion of the viaduct replacement program, we estimate a total provisional budget need of $223 million. That reflects a potential increase of 6.6 percent. These are preliminary estimates and we will continue to refine them as work progresses.

    Next steps

    WSDOT has notified the Washington State Legislature of the program’s cash flow needs for the 2017-2019 budget cycle and will work with the Legislature through the budgeting process. Our immediate focus is addressing the up to $60 million needed as a result of the tunneling delay.  The next 18 months of construction will tell us a great deal about the program’s funding needs beyond the current biennium.

    “We remain committed to completing this important safety project while also protecting taxpayers,” said Roger Millar, Acting Transportation Secretary, “We will continue to follow the terms of the design-build contract to recover the added costs that are due to the delay of the project.” 

    This includes pursuing insurance claims, identifying potential cost savings in other elements of the program and ongoing litigation to recover damages. If efforts to recover costs are successful, the funds would likely not be available until after the project is complete.

    We will continue to provide additional details about the program’s budget needs as the 2017 legislative session approaches. In the meantime, our focus will remain where it always has: on delivering the tunnel and replacing the Alaskan Way Viaduct for the people of Washington.

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  • July 19 project update: Seattle Tunnel Partners resumes mining

    Seattle Tunnel Partners resumed mining yesterday following a month of routine and hyperbaric maintenance on Bertha, the SR 99 tunneling machine. Crews inspected and repaired machine components as needed during the maintenance period, which started on June 23. 
     
    The maintenance period included more than 40 shifts of work under hyperbaric conditions, changing cutting tools and performing other maintenance in the space behind the cutterhead. In all, STP changed 33 of more than 700 cutting tools. 
     
    Be sure to check out recently released videos of hyperbaric work and the highway construction that is ongoing in the tunnel behind the tunneling machine. 
     
    What’s next for Bertha?
     
    Tunnel boring is one-third complete. The machine is located approximately 120 feet beneath Spring Street, tunneling north toward First Avenue. At its deepest point near Virginia Street, the machine will be more than 200 feet below the surface.
     
    STP expects to stop two more times for maintenance before they reach the future north portal, near the Space Needle. You can continue to follow tunneling progress at our Follow Bertha page, and on Twitter @BerthaDigsSR99.
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    Order: 1.2

  • July 11 project update: New video shows that changing Bertha's cutting tools is no easy task

    Seattle Tunnel Partners crews are making good progress as they continue performing routine maintenance on Bertha, the SR 99 tunneling machine.
     
    The machine has been stopped approximately 120 feet below Spring Street, just west of First Avenue, since June 23. There, crews have been checking and maintaining equipment, and are on schedule to resume mining by the end of the month. 
     
    Much of their focus is on inspecting and, when needed, replacing the cutting tools that scrape away the earth in front of the machine. This work must be completed in hyperbaric conditions similar to those found in an underwater dive (this post explains hyperbaric work in greater detail).
     
    These conditions require workers to adjust their bodies to greater air pressure than we live and breathe in every day. Crews are only able to spend approximately one hour working in this increased air pressure. As a result, five crews of seven people take turns replacing the tools and performing other work in the space behind the cutterhead.   
     
    Bertha’s cutterhead is outfitted with more than 700 tools. So far, STP has replaced only 25 of the more than 400 tools they’ve inspected during this maintenance stop. 
     
    New video captured by STP shows that performing maintenance on the cutterhead is no easy task. In addition to working in hyperbaric conditions, crews must complete their work in a confined space. The cutting tools shown in the video weigh approximately 75 pounds.
     
     
    We’ll continue to provide additional updates as STP’s work progresses.
     
    Recent tunneling updates 
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  • June 28 project update: New videos show crews at work inside the SR 99 tunneling machine

    Over the next several weeks, specialized crews will complete routine cutterhead maintenance at the front end of Bertha, the SR 99 tunneling machine. To safely do this, crews must stabilize the ground in front of the machine. They do this by injecting a type of clay, known as bentonite, into the front end of the machine. This creates a seal that prevents water and soil from entering – and air from escaping – their work space. 
     
    Next, crews over-pressurize the space by introducing compressed air, which pushes against the bentonite to counteract the ground and water pressure at the front end of the machine. This newly created "hyperbaric" work space has pressure levels that are higher than regular atmospheric pressure, similar to conditions found in an underwater dive. The graphic below illustrates the process.
     
       
     
     
    New videos
    Preparations for this work are underway now that Bertha has stopped for planned maintenance beneath Spring Street. Crews expect to make their first “hyperbaric intervention” next week. Seven, five-member crews will work around the clock to perform maintenance in the space behind the cutterhead. 
     
    Each crew member must spend several minutes in a special chamber to prepare for the greater pressures they’ll experience while working in hyperbaric conditions. The amount of time that crews can safely work in these conditions varies depending on the pressure of the hyperbaric work space. In previous interventions on this project, crews were able to spend up to an hour in these conditions before decompressing and returning to the surface. 
     
    The video below shows the chambers crews use to adjust to hyperbaric conditions and enter the space behind the cutterhead.
     
     
    The video below was provided by Ballard Marine Construction, the firm responsible for completing this work on the tunnel project. It shows crews at work behind Bertha’s cutterhead during a planned maintenance stop earlier this spring.
     
     
    The duration of the maintenance stop will depend on the extent of the work that’s needed. STP’s previous maintenance stop near Yesler Way lasted approximately six weeks. We’ll continue to provide updates as their work progresses.
     

     

    — more —
  • Construction highlights for Friday, July 8 - Friday, July 15

    North end

    Plan ahead: Beginning Tuesday, July 18 for approximately two weeks
    • The bus lane of southbound SR 99 will be closed at three locations of Valley, Raye and Comstock streets from 8 p.m. to 5 a.m. weeknights.
    — more —
  • June 23 project update: Tunnel crews arrive at planned maintenance stop

    It’s a reality faced by all car owners: Every few thousand miles, it’s time for an oil change. The same principle applies to tunneling machines, which experience normal wear and tear as they grind their way through the earth.

    And so, after more than 1,500 feet of tunneling since their last pit stop, Seattle Tunnel Partners crews are set to begin regular maintenance on the massive machine. The front end of the cutterhead is now located approximately 120 feet beneath Spring Street, near Post Avenue. It will remain at that location for planned inspections and maintenance that are expected to last several weeks, though the duration of the stop will ultimately depend on the extent of the maintenance needs.

    Performing regular maintenance is a critical part of ensuring the tunneling machine remains in good working order. All tunneling machines, no matter how large or small, need routine maintenance. STP will assess the condition of various systems throughout the machine over the next several days. This assessment will help them determine how much maintenance needs to be completed.

    Crews are already preparing for their most challenging task: inspecting and replacing the tools that cut the ground in front of the machine. These tools wear down and may need replacement multiple times during the course of the tunnel drive. Inspecting and replacing the tools is challenging because it requires crews to work in hyperbaric conditions. For a detailed explanation of hyperbaric work, see Monday’s post.    

    Tracking progress

    To date, crews have tunneled 3,088 feet, or nearly one-third of the total bored tunnel length. Almost half of their overall progress was accomplished in the past eight weeks. Crews have now installed a total of 466 concrete tunnel rings.

    When all necessary machine maintenance is complete, crews will resume tunneling toward First Avenue. Our Follow Bertha page contains tunneling statistics and information about the conditions crews will face as they continue mining toward the north end of downtown. You can also follow progress on Twitter @BerthaDigsSR99.

     

     

    — more —
  • June 20 project update: Tunnel crews nearing planned maintenance stop

    After another week of good tunneling progress, Seattle Tunnel Partners is preparing Bertha, the SR 99 tunneling machine, for its next planned maintenance stop.
     
    STP crews have now mined a total of 2,971 feet and installed 449 concrete tunnel rings. The top of the tunneling machine is located approximately 120 feet below Post Avenue, between Madison and Spring streets.
     
    Crews have mined nearly 1,500 feet since Bertha’s previous planned maintenance stop near Yesler Way. STP plans to stop soon because the soils in the area are dense and stable, providing more suitable conditions for maintenance. The stop could begin this week and is expected to last several weeks, depending on the extent of maintenance needs. STP’s previous maintenance stop lasted six weeks.
     
    Over the course of the first week, STP will perform a thorough inspection of various systems throughout the machine. This inspection will help STP verify how much maintenance work is needed. Crews will then prepare to inspect the cutting tools that cut the ground in front of the machine, and replace these tools as needed. These tools wear down over time and must be replaced multiple times during the course of the tunnel drive. 
     
    Hyperbaric work
     
    Before crews can inspect and replace cutting tools, they must first stabilize the ground in front of the tunneling machine. They do this by using compressed air and a type of clay, known as bentonite, to create an air bubble. This air bubble allows them to safely work in the area behind the cutterhead, which would otherwise be filled by soil and water. 
     
    Before crews can safely work in this environment, they must first adjust their bodies to air pressure that is greater than the atmosphere we live and breathe in every day. It's the same process scuba divers go through during the course of an underwater dive, but STP’s workers won't need diving gear. Instead they will spend approximately an hour inside specialized pressure chambers within the machine that help their bodies adapt to these ‘hyperbaric’ conditions. The graphics below illustrate the process.
     
    (Click the image above for a larger view)
     
    When all necessary maintenance is complete, crews will resume tunneling toward First Avenue. Our next regular progress update is slated for Thursday, but we’ll post something sooner if crews reach the maintenance stop before then.
     

     

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  • New SR 99 off-ramp construction starts this summer

    Construction will soon begin on a new flyover off-ramp designed to connect the northbound lanes of State Route 99 to Seattle’s stadiums, Pioneer Square and downtown Seattle.

    The Washington State Department of Transportation awarded the $3.56 million contract to Interwest Construction, Inc. of Burlington, Wash., to build the ramp to South Dearborn Street, which will allow northbound traffic to exit in Seattle’s SODO neighborhood when the new SR 99 tunnel opens. The ramp will be built within the existing SR 99 work zone near the stadiums, so it should not have much effect on drivers in the area.

    WSDOT and Interwest expect to sign a contract giving notice to proceed in the coming weeks. Construction activities are expected to start in July and last approximately six months. The new off-ramp will open to motorists at the same time as the new SR 99 tunnel, currently scheduled for 2018.

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  • June 13 project update: Bertha passes the half-mile mark

    Seattle Tunnel Partners has now bored more than one-half mile of the SR 99 tunnel. 
     
    As of June 13, Bertha, the SR 99 tunneling machine, had traveled a total of 2,724 feet and installed 411 concrete rings. Crews have tunneled more than 1,100 feet since leaving the machine’s most recent planned maintenance stop near Yesler Way on April 29. The completed bored tunnel will be 9,270 feet. 
     
    The top of the machine’s cutterhead is approximately 115 feet below Madison Street, east of Western Avenue. It’s approaching the southern edge of Zone 4, which continues the tunnel’s path toward First Avenue.
     
    STP has begun preparing for its next planned maintenance stop. The details of the stop are still being developed, but it will likely occur sometime in July. During the stop, STP crews will inspect the machine and perform cutterhead maintenance, a process that could take several weeks.
     
    Bertha now climbing
    After steadily descending over the first part of the tunnel drive, Bertha has now begun climbing toward her eventual exit point near the Space Needle. Interestingly, the lowest spot in the tunnel isn’t its deepest point underground. Due to the city’s topography, the top of the tunnel will be more than 200 feet below the surface near Virginia Street. 
     
    The map on the Follow Bertha page allows you to see the depth of the tunnel at each point along its path between the south and north ends of downtown. You can also take a virtual tour of the tunnel route by watching the underground simulation below. 
     
     
     
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  • Marathon to close northbound SR 99 through downtown Seattle June 18

    The 2016 Seattle Rock and Roll Marathon will close northbound SR 99 through downtown Seattle on Saturday, June 18. Northbound SR 99 will be closed from South Spokane Street to Harrison Street between approximately 5 a.m. and 3 p.m.
     
    Although the marathon is scheduled to last until 3 p.m., the Seattle Department of Transportation is planning to reopen SR 99 and the Alaskan Way Viaduct as early as possible once the runners have passed this part of the course. Please refer to the event website for more specific information on other road closures and parking restrictions related to the event.
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  • Construction Highlights for Friday, June 17 - Friday, June 17, 2016

    North End

     
    Monday, June 20 to Wednesday, June 22
    • Two right lanes of southbound SR 99 will be closed between Valley and Mercer streets from 10 p.m. to 5 a.m. each night.

     

    Thursday, June 23
    • The right lane of southbound SR 99 will be closed between Valley and Mercer streets from 10 p.m. Thursday to 5 a.m. Friday.
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  • May 31 project update: Tunnel boring 25 percent complete

    As of May 31, Seattle Tunnel Partners crews have tunneled a total of 2,314 feet. Tunnel boring is now 25 percent complete. 
     
    Bertha is located in zone 3 of the tunnel drive. The top of the machine is approximately 105 feet below the surface, approaching Marion Street.
     
    Look for another progress update on Thursday. 
     

     

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  • May 26 project update: Bertha reaches Western Avenue

    Seattle Tunnel Partners crews have successfully tunneled beneath the Columbia Street on-ramp to the Alaskan Way Viaduct. Bertha, the SR 99 tunneling machine, passed approximately 50 feet below the structure’s foundations and is now beneath Western Avenue, heading toward Marion Street. The on-ramp, like the viaduct, remains stable.
     
    As of May 26, Bertha had traveled a total of 2,255 feet. She is in zone 3 of the tunnel drive. The top of the tunneling machine is now more than 100 feet below the surface. 
     
    Look for another progress update on Tuesday, May 31, following the holiday weekend.  
     

     

    — more —
  • Traffic alert: Rolling slowdowns on the viaduct May 19-26

    Drivers on northbound SR 99 should plan ahead for daytime slowdowns over the next week as a movie is filmed on the Alaskan Way Viaduct. The production will film on the northbound deck the viaduct between South Atlantic Street and Western Avenue. Traffic will not be stopped, but there will be rolling slowdowns as filming moves along the structure. The slowdowns will occur during the hours listed below:

    • Thursday, May 19 - 9 a.m. to 3 p.m.
    • Friday, May 20 - 9 a.m. to 3 p.m.
    • Saturday, May 21 - 7 a.m. to 3 p.m.
    • Sunday, May 22 - 7 a.m. to 8 p.m.
    • Wednesday, May 25 - 9 a.m. to 3 p.m., and 7 p.m. to 8 p.m.
    • Thursday, May 26 - 9 a.m. to 3 p.m.
     

    Visit the Seattle Department of Transportation's blog for additional information about the film production.

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    Order: 1

  • May 18 project update: Bertha passes 2,000-foot mark

    Seattle Tunnel Partners resumed mining late Tuesday evening following a break for rest and routine maintenance.
     
    Bertha has now installed 300 concrete tunnel rings and traveled more than 2,000 feet from the launch pit west of the stadiums. Her journey is more than 20 percent complete. She is approaching the start of Zone 3, which will take her beneath the Columbia Street on-ramp to the viaduct and, later, beneath Western Avenue. Look for twice-weekly updates on the Follow Bertha page.
     
    — more —
  • May 11 project update: Bertha fully beyond Alaskan Way Viaduct

    Bertha’s passage beneath the Alaskan Way Viaduct has officially come to an end, but Seattle Tunnel Partners has decided to continue mining a bit farther before taking a short break.
     
    By early Wednesday morning, crews had tunneled 385 feet since the underground maintenance stop near Yesler Way. That put them clear of the fourth and final viaduct column the machine had to pass to complete its journey under the elevated structure. STP decided to mine beyond 385 feet in order to reach a better location for the machine to stop while crews take a few days to rest after mining around the clock since April 29. 
     
    SR 99 was closed for 10 days while Bertha tunneled beneath the viaduct. WSDOT reopened the highway on Sunday evening based on STP’s tunneling progress and the continued stability of the ground and viaduct. Monitoring of the structure and ground will continue throughout the remainder of the tunnel drive.  
     
    Look for another progress update next week.
     

    Recent updates 

     
    For earlier program updates, please visit our archive page.

     

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    Order: 1.2

  • May 9 #99closure wrap-up

    Commuters were treated to a welcome sight when they hit the roads Monday morning: a fully reopened Alaskan Way Viaduct. SR 99 through downtown Seattle was open to traffic by Sunday evening following a 10-day closure to allow the SR 99 tunneling machine to pass beneath the viaduct.
     
    We’d like to thank travelers again for the patience and flexibility throughout the closure. Many folks took the opportunity to explore new ways of getting around, and we hope commuters continue to consider using alternatives to driving alone going forward.
     
    Tunneling progress
    Seattle Tunnel Partners has installed 52 rings since mining resumed on April 29. Crews have excavated 342 feet of the approximately 385 feet of tunnel to be completed beneath the Alaskan Way Viaduct. STP has told us they will take a short break from tunneling after they reach the 385-foot mark so crews can rest.
     
    Visit our tracking page to see a map showing Bertha’s progress.
     
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  • Alaskan Way Viaduct open

    Update posted at 7:45 p.m.
     
    The Alaskan Way Viaduct is now open in both directions.
     
    Tunneling progress
     
    Seattle Tunnel Partners has installed 49 rings since mining resumed last week. Crews have excavated 318 feet of the approximately 385 feet of tunnel to be completed beneath the Alaskan Way Viaduct.
     
    Visit our tracking page to see a map showing Bertha’s progress. 
     

    Successful tunnel drive means an early opening for SR 99 through Seattle  

    After 10 days of around-the-clock tunneling, Bertha’s biggest hurdle is now behind her. That hurdle – the Alaskan Way Viaduct she was built to replace – will reopen for the Monday morning commute, bringing an early end to the much-anticipated closure.   

     
    Structural engineers with the Washington State Department of Transportation completed a thorough inspection of the viaduct on Sunday. Their inspection confirmed what a team of engineers observed throughout the past 10 days of tunneling: continued stability of the ground and the viaduct. 
     
    By Friday, the machine had successfully tunneled through complex soils only 15 feet below the viaduct’s foundation – the closest the machine will come to any structure at any point in its drive beneath Seattle. On Sunday, STP completed installation of the rings beneath this critical location, clearing the way for the final inspection and the early opening of the highway. WSDOT’s 24-hour command center will remain open until the machine has successfully tunneled 385 feet, the distance at which it will be completely clear of the viaduct. 
     
    Tunneling progress
    Seattle Tunnel Partners has installed 47 rings and excavated 312 feet of the approximately 385 feet of tunnel to be completed beneath the Alaskan Way Viaduct. Crews continue to work around the clock to tunnel, build rings and perform ongoing machine maintenance.
    Visit our tracking page to see a map showing Bertha’s progress.
     
    WSDOT worked closely with Seattle Department of Transportation, Seattle Police Department, King County Metro, King County Water Taxi, Sound Transit, Community Transit and the Port of Seattle to keep traffic moving and provide travel options during the closure.
     
    We are extremely grateful to those commuters that shifted their travel routes and timing during the Alaskan Way Viaduct closure. Every person that chose alternate transportation helped to reduce traffic regionally. Thank you for all your efforts.
     
    Here’s what you need to know about transportation service revisions in the next few days.
     
    Water Taxi resumes regular service Tuesday morning, May 10
     
    Metro Transit returns to regular routing Monday, May 9
    • King County Metro Transit service will resume regular routing via the Alaskan Way Viaduct with the start of service Monday morning. At that time, the bus stop on Columbia Street at Second Avenue will also reopen.  
    • Current surface street reroutes through SODO and temporary stops remain in effect for the remainder of Sunday, May 8.
     
    Restrictions on city streets lifted for Monday morning commute
    • With the exception of parking restrictions along Harbor Avenue in West Seattle, temporary city street restrictions put in place for the closure will be lifted before Monday morning.

     

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    Order: 1.1

  • May 8 #99closure update

    May 8 update | Posted at 3:55 a.m.

    Tunneling progress

    Seattle Tunnel Partners has installed 44 rings and excavated 292 feet of the approximately 385 feet of tunnel to be completed beneath the Alaskan Way Viaduct. Crews continue to work around the clock to tunnel, build rings and perform ongoing machine maintenance.

    Visit our tracking page to see a map showing Bertha’s progress. We will provide another update this afternoon.

    Weekend events

    Several events happening in Seattle today could affect traffic patterns. We encourage people to plan ahead. Visit our maps and resources page for trip-planning tools:

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  • May 7 #99closure update

    Update posted at 2:45 p.m.

    Tunneling progress

    Seattle Tunnel Partners has installed 40 rings since mining resumed last week. Crews have excavated 266.5 feet of the approximately 385 feet of tunnel to be completed beneath the Alaskan Way Viaduct.

    Visit our tracking page to see a map showing Bertha’s progress.

    Weekend events

    If you’re heading out this weekend, please be aware of several events happening in Seattle that could affect traffic patterns. Remember to plan ahead and visit our Maps and Resources page for trip-planning tools:

    • Saturday: Sounders game at 7 p.m.
    • Sunday: Color Run happening. Route snakes from Seattle Center down Fourth Avenue to Seneca Street
    • Sunday: Mother’s Day! If you are heading to the Seattle waterfront, take advantage of up to 4 hours of free parking at participating garages: http://www.downtownseattle.com/downtown-parking/mothers-day/

     


    May 7 update | Posted at 3:55 a.m.
     

    Tunneling progress

    Seattle Tunnel Partners has installed 37 rings since mining resumed last week. Crews have excavated 246 feet of the approximately 385 feet of tunnel to be completed beneath the Alaskan Way Viaduct.

    Visit our tracking page to see a map showing Bertha’s progress. We will provide another update this afternoon.

    Weekend events

    Several events happening in Seattle this weekend will affect traffic patterns. We encourage people to plan ahead. Visit our maps and resources page for trip-planning tools:
    • Saturday: Montlake Bridge will be closed (10 a.m. – 3 p.m.) for the opening day of boating season and the Windermere Cup
    • Saturday: Sounders game at 7 p.m.
    • Sunday: Color Run happening. Route snakes from Seattle Center down Fourth Avenue to Seneca Street
    • Sunday: Mother’s Day! If you are heading to the Seattle waterfront, take advantage of up to 4 hours of free parking at participating garages.

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    Order: 1.2

  • May 6 #99closure update

    May 6 update | Posted at 8 p.m.

    Tunneling progress

    Seattle Tunnel Partners has installed 35 rings since mining resumed last week. Crews have excavated 234 feet of the approximately 385 feet of tunnel that must be completed before the Alaskan Way Viaduct reopens to traffic.

    Visit our tracking page to see a map showing Bertha’s progress. We will provide another update this evening.

    Morning commute recap

    Highways: Traffic on most freeways backed up earlier than normal and was consistently worse than a normal Friday afternoon due to multiple incidents such as collisions in both directions of I-5 in Shoreline, a handful on I-405 and on eastbound I-90 in Mercer Island. Northbound I-5 heading out of Seattle was again faster than normal, but not as fast as all previous afternoon commutes since the viaduct closure began. The commute is taking longer than normal to ease down.

    Seattle surface streets: Congestion was heavier than normal on most Seattle surface streets, especially on eastbound West Seattle Bridge, 1st Avenue South, Mercer Street, Denny Way, Northeast 45th Street and Northeast 50th Street. The southbound Aurora Avenue North left-turn lane to Denny Way was open until 3:40 p.m., when it was closed because it was causing backups on Aurora.

    Changes and improvements

    In response to feedback and traffic conditions, SDOT will remove the southbound left turn restriction at Aurora and Denny for the remainder of the weekend.

    Weekend events

    Several events happening in Seattle this weekend will affect traffic patterns. We encourage people to plan ahead. Visit our Maps and Resources page for trip-planning tools:

    • Saturday: Montlake Bridge will be closed (10 a.m. – 3 p.m.) for the opening day of boating season and the Windermere Cup
    • Saturday: Sounders game at 7 p.m.
    • Sunday: Color Run happening. Route snakes from Seattle Center down Fourth Avenue to Seneca Street
    • Sunday: Mother’s Day! If you are heading to the Seattle waterfront, take advantage of up to 4 hours of free parking at participating garages.

     

    Bicycles and pedestrian access prohibited on the viaduct

    As a reminder, trespassing onto the viaduct is against the law. Police will be patrolling throughout the night. 


    May 6 update | Posted at 11 a.m.

    Tunneling progress

    Seattle Tunnel Partners has installed 32 rings since mining resumed last week. Crews have excavated  214 feet of the approximately 385 feet of tunnel that must be completed before the Alaskan Way Viaduct reopens to traffic.

    Visit our tracking page to see a map showing Bertha’s progress. We will provide another update this evening.

    Morning commute recap

    Highways: WSDOT saw mostly normal Friday morning commute times, with the continuing exception of SeaTac northbound to Seattle experiencing heavy congestion. Eastside commuters faced a 15-20 minute longer commute than a normal Friday, due to multiple closures both directions on I-405.

    Seattle surface streets: As we have seen in previous mornings, traffic heading into Seattle is heavy on First Avenue South, Fourth Avenue South and on the West Seattle Bridge. An injury collision on the West Seattle Bridge blocked eastbound lanes, creating heavy backups. SDOT contacted the U.S. Coast Guard to request that swing bridge openings be restricted until 9 a.m. to help with traffic.

    Changes and Improvements

    In response to feedback and traffic conditions, SDOT is removing the southbound left turn restriction at Aurora and Denny until 3 p.m. today. Traffic engineers will reevaluate at 3 p.m. whether to keep the restriction.

    SDOT has installed a portable bike corral at Seacrest Park in West Seattle to help with increased demand for bike parking.

    Weekend Events

    Several events happening in Seattle this weekend will affect traffic patterns. We encourage people to plan ahead. Visit our Maps and Resources page for trip-planning tools:

    • Saturday: Montlake Bridge will be closed (10 a.m. – 3 p.m.) for the opening day of boating season and the Windermere Cup
    • Saturday: Sounders game at 7 p.m.
    • Sunday: Color Run happening. Route snakes from Seattle Center down Fourth Avenue to Seneca Street
    • Sunday: Mother’s Day! If you are heading to the Seattle waterfront, take advantage of up to 4 hours of free parking at participating garages.

     


    May 6 update | Posted at 4 a.m.

    Tunneling progress

    Seattle Tunnel Partners has installed 31 rings since mining resumed last week. Crews have excavated 208 feet of the approximately 385 feet of tunnel that must be completed before the Alaskan Way Viaduct reopens to traffic.

    Visit our tracking page to see a map showing Bertha’s progress. We will provide another update later this morning.

    Stay informed and know before you go

    We’re asking travelers to continue using alternate means to get to work. If you’re driving, check traffic conditions before you get on the road. Here's a few viaduct closure commuter tips:

    • Take the bus, train, or water taxi to work. Bus commuters should check to see the changes in place for routes that normally use the viaduct.
    • Commuters can ride free in a vanpool during the 99 closure that has an available seat under the Ticket to Ride program.
    • Bike to work.
    • Adjust your work hours or work from home.
    • Have a backup plan for picking up and dropping off children at daycare and after-school activities.
    • Know before you go – using WSDOT's travel tools or SDOT’s traveler information page.

     

    Visit our website often and follow @WSDOT_Traffic and @BerthaDigsSR99 as the #99 closure continues. We’ll be posting regular updates about traffic conditions and tunneling progress.

     

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  • May 5 #99closure update

    May 5 update | Posted at 8:00 p.m.

    Tunneling progress

    Seattle Tunnel Partners has installed 29 rings since mining resumed last week. Crews have excavated 195 feet of the approximately 385 feet of tunnel that must be completed before the Alaskan Way Viaduct reopens to traffic. 

    Visit our tracking page to see a map showing Bertha’s progress. We will provide another update in the morning.

    Evening commute recap

    Highways: Although congestion started earlier than normal, travel times were at or just slightly above normal (by up to 15 minutes) for a Thursday afternoon. There were no significant blocking incidents. The one exception continues to be northbound I-5 from Seattle to Lynnwood, where traffic has been significantly lighter than normal since the viaduct closure began.

    Seattle surface streets: Protests at 5th Avenue and James Street and 7th Avenue and Stewart Street slowed the afternoon commute downtown, especially for transit trying to access the express lanes on-ramp at 5th Avenue and Cherry Street. With the exception of southbound congestion on 1st Avenue South and 15th Avenue West, traffic on most streets was just a little worse than normal.

    Mass Transit: Riders experienced delays on King County Metro bus routes affected by #99closure. Standby coaches ran primarily on the 5, 21, 120, 121, 123 and the C Line to help maintain schedules. The Water Taxi continues to see strong ridership to West Seattle; however, some capacity remained with no schedule delays.

    As a reminder, live traffic maps can help you make informed travel choices as you are about to hit the road. We appreciate commuters’ continued patience and support through this closure.

     

    May 5 update | Posted at 11 a.m.

    Tunneling progress

    Seattle Tunnel Partners has installed 27 rings since mining resumed last week. Crews have excavated 182 feet which is nearly halfway through the approximately 385 feet of tunnel that must be completed before the Alaskan Way Viaduct reopens to traffic.   
     
    Visit our tracking page to see a map showing Bertha’s progress. We will provide another update this evening. 
     
    Morning commute recap
     
    Highways:  Thursday’s northbound commutes into Seattle and Bellevue started early and extended into the late morning hours. Commuters on the Eastside encountered additional congestion due to an emergency expansion joint repair on northbound Interstate 405. Even with repairs taking only 20 minutes, that back-up created a bumper to bumper jam on I-405. This is just a reminder that during the #99closure, all commuters need to expect the unexpected and plan for possible delays each day.
     
    Seattle surface streets: As we have seen in previous mornings, traffic heading into Seattle is heavy on First Avenue South, Fourth Avenue South and on the West Seattle Bridge. Trucks waiting to enter the Port of Seattle’s Terminal 46 extended south on East Marginal Way South, slowing drivers and buses. 
     
    WSDOT, SDOT and King County continue to work together to monitor traffic conditions and discuss any adjustments during conference calls held three times per day. We appreciate drivers’ patience during this closure and encourage everyone that can to explore alternate travel modes and avoid the peak commute hours.
     

     

    May 5 update | Posted at 4 a.m.

    Tunneling progress

    Seattle Tunnel Partners has installed 26 rings since mining resumed last week. Crews have excavated 175 feet of the approximately 385 feet of tunnel that must be completed before the Alaskan Way Viaduct reopens to traffic.

    Visit our tracking page to see a map showing Bertha’s progress. We will provide another update this afternoon.

    Get ready for Thursday’s commute

    We're continuing to urge commuters who have made changes to keep using alternative means to get to work, and for those who have not made changes to consider doing so, as traffic remains challenging throughout the Puget Sound Region. Our resources page can help you plan your commute. 
     

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  • May 4 #99closure update

    May 4 update | Posted at 7:30 p.m.
     
    Tunneling progress
     
    Seattle Tunnel Partners has installed 25 rings since mining resumed last week. Crews have excavated 162.5 feet of the approximately 385 feet of tunnel that must be completed before the Alaskan Way Viaduct reopens to traffic. 
     
    Visit our tracking page to see a map showing Bertha’s progress. We will provide another update in the morning.
     
    Evening commute recap
     
    Highways: Congestion on southbound I-5 into Seattle started early due to a collision that blocked the HOV lane near Union Street in downtown for about 15 minutes just after noon. Traffic on all other highways was fairly typical or just slightly slower than normal for a Wednesday afternoon. Northbound I-5 traveling out of Seattle was faster than normal.
     
    Seattle surface streets: First Avenue South and Fourth Avenue South were congested throughout the commute because of train blockages on Holgate and Lander earlier in the afternoon. All local streets leading to I-5 were heavier than normal, with the Olive/Howell corridor especially slow because of a high volume of vehicles exiting the parking garages.
     
    The U.S. Coast Guard has also asked mariners to limit drawbridge openings during the #99closure to help keep traffic in the city moving. Travelers can also help out by continuing to plan ahead, traveling early or late and by checking traffic conditions before hitting the road.
     
    Over the last two days, SDOT recorded over 5,000 cyclists per day across the Fremont Bridge and over 2,300 across the West Seattle Swing Bridge - a new record!
     
    Mass Transit: King County Metro routes affected by the closure were running delays of approximately 20 minutes. Standby coaches ran primarily on the 5, 21, 120 and the C line to maintain schedules. Water Taxi sailings to West Seattle still had capacity this evening with no delays.

     

    Update 5/4/16 11:10 a.m. - corrected number of rings and distance traveled

    May 4 update | Posted at 10:45 a.m.

    Tunneling progress

    Seattle Tunnel Partners has installed 22 rings since mining resumed last week. Crews have excavated 149 feet of the approximately 385 feet of tunnel that must be completed before the Alaskan Way Viaduct reopens to traffic. This morning, crews have been busy doing maintenance on the machine, which is an important part of the tunneling operation.

    Visit our tracking page to see a map showing Bertha’s progress. We will provide another update this evening.

    Morning commute recap

    Highways:  Wednesday’s commute for northbound drivers started earlier than usual, similar to other mornings we’ve seen during the #99closure. Commutes on SR 167 and I-405 were heavy as well, about 10 minutes above average.

    Seattle surface streets: Heavy traffic heading eastbound on the West Seattle Bridge started a bit earlier than normal this morning. First Avenue South and Fourth Avenue South continue to see increased congestion. Continue to plan ahead, travel early or late and check traffic conditions before you hit the road.     

     

    Update 5/4/16 11:10 a.m. - corrected number of rings and distance traveled 

    May 4 update | Posted at 4 a.m.

    Tunneling progress

    Seattle Tunnel Partners has installed 22 tunnel rings since mining resumed last week. As of 4 a.m. on Wednesday, May 4, crews had excavated 149 of approximately 385 feet needed to reopen the viaduct. Visit our tracking page to see a map showing Bertha’s progress. Look for another progress update this afternoon. 

    Also, if you missed the drone video we posted yesterday, you can watch it here (links to YouTube).

    Know before you go
    As the Wednesday morning commute begins, we’re asking travelers to continue to plan ahead and adjust their commutes. Make sure you check travel times before you hit the road this morning. Several incidents yesterday illustrated that a single collision can quickly change the state of traffic. Thanks for your continued patience.

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  • May 3 #99closure update

    May 3 evening update Posted at 8 p.m.

    Tunneling progress

    Seattle Tunnel Partners has installed 20 rings since mining resumed last week. Crews have now excavated 131 feet of the approximately 385 feet of tunnel that must be completed before the Alaskan Way Viaduct reopens to traffic.

    Visit our tracking page to see a map showing Bertha’s progress. If you’re up early to beat the commute, look for our next update around 4 a.m.

    Evening commute recap

    Highways: Traffic on most highways were fairly typical or just slightly slower than normal for a Tuesday afternoon. Like Friday and Monday, northbound I-5 heading out of Seattle was actually faster than normal until a rollover crash around 5:15 p.m. that blocked three left lanes near Lake City Way. This is a good reminder that a single collision can quickly change the state of traffic – make sure you check travel times before you leave and explore commute alternatives (PDF) as the week progresses.

    Seattle surface streets: Seattle surface streets were a little slower than normal for a Tuesday afternoon. Traffic was especially slow on 4th Avenue in downtown, causing transit-related delays. The northbound I-5 rollover crash near Lake City Way had a minimal effect on surface streets as city and state DOTs diverted most traffic on to the express lanes.

    Observationally, bike counts were heavy on the Spokane Swing Bridge and Fremont Bridge. No final numbers yet, but we’re expecting record-breaking ridership– keep up the good work!

    Denny Way - WSDOT and SDOT have been working closely on a number of strategies to help keep traffic moving during the #99closure. Left turns from southbound Aurora Avenue North to Denny Way have been restricted on weekdays as part of this plan. This restriction allows additional signal time for northbound traffic entering SR 99 in this area. Southbound drivers wanting to head eastbound on Denny Way can turn right at John Street and then turn left from Sixth Avenue North to Denny Way at the signal.

    SDOT has also adjusted the traffic control on southbound Aurora in order to allow vehicles entering the Battery Street Tunnel to bypass vehicles waiting to exit at Denny Way. They continue to monitor this intersection.

    Mass Transit: King County Metro routes affected by the closure were running delays of approximately 20 minutes. Standby coaches ran primarily on the 120 and the C line to maintain schedules. Water Taxi sailings to West Seattle were at or near capacity this afternoon. 


    May 3 afternoon update | Posted at 11 a.m.

    Tunneling progress

    Seattle Tunnel Partners has installed 17 rings since mining resumed last week. Crews have now excavated 117 feet of the approximately 385 feet of tunnel that must be completed before the Alaskan Way Viaduct reopens to traffic.

    Visit our tracking page to see a map showing Bertha’s progress. We will provide another update this evening.

    Morning commute recap

    Highways:  WSDOT’s Incident Response Team quickly pushed an early morning rollover crash at Boeing Field to the side of northbound I-5 but even this brief closure had a ripple effect throughout the region with northbound commuters. WSDOT saw extended congestion on northbound I-5 as well as heavier than normal volumes and congestion on northbound SR 167 and northbound I-405 in the Renton area.

    Seattle surface streets:
    Seattle streets this morning continued to show increased congestion, as expected. Northbound traffic on Fourth Avenue South heading into downtown was heavy, similar to last Friday morning’s commute. We encourage drivers to continue to plan ahead and leave early or late to avoid traveling during the busiest peak commute hours.   

    Transit: The King County Water Taxi continues to serve large numbers of riders with two West Seattle sailings at capacity Monday evening. Additional improvements for pedestrian queuing on both the Seattle and West Seattle docks are in the works for laer today. We appreciate everyone’s patience and commend riders for choosing an alternate mode of transportation to get to downtown Seattle. 

     

    May 3 morning update | Posted at 4 a.m.

     
    Tunneling progress

    As of 4 a.m. Tuesday morning, May 3, Seattle Tunnel Partners had installed 16 tunnel rings since mining resumed last week. Crews have now excavated 106 feet of the approximately 385 feet of tunnel that must be completed before the Alaskan Way Viaduct reopens to traffic.

    Visit our tracking page to see a map showing Bertha’s progress. Look for another update this afternoon.

    Get a head start on the morning commute

    As we begin the morning commute, we’re reminding travelers to plan ahead and give themselves extra time to reach their destination. Go to our maps and resources page or see our travel alternatives handout to explore options other than driving. Thanks for your continued patience as we work to complete this important phase of the tunnel project.

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  • May 2 #99closure update

    May 2 Evening Update | Updated 8 p.m.

     

    Tunneling progress

    As of Monday evening, Seattle Tunnel Partners has installed 14 rings since mining resumed last week. Crews have now excavated 91 feet of the approximately 385 feet of tunnel that must be completed before the Alaskan Way Viaduct reopens to traffic.

    Visit our tracking page to see a map showing Bertha’s progress. Going forward, we will update the Bertha tracker one to three times per day. Look for the next update early tomorrow morning.

    Evening commute recap

    Highways: Drivers did a great job of making plans and finding alternatives to their regular commutes. Commute times around 5pm were close to average for a typical Monday evening. We encourage drivers to keep vigilant and explore commute alternatives (PDF), as we expect heavier commutes as the week progresses.

    Seattle surface streets: While midday traffic moved well, downtown Seattle traffic became heavy during the evening commute. A signal issue that disrupted signal timing in places downtown, and several incidents with Metro buses, both contributed to delays.

    Mass Transit: King County Metro deployed a number of standby buses to maintain schedules, while the King County Water Taxi’s 5:15 pm sailing from Seattle sold out. The Water Taxi is using a standby vessel to keep sailings on time.


    May 2 early update | 12:02 p.m.

    Tunneling progress

     
    As of Monday morning, May 2, Seattle Tunnel Partners has installed 11 rings since mining resumed last week. Crews have now excavated 78 feet of the approximately 385 feet of tunnel that must be completed before the Alaskan Way Viaduct reopens to traffic. 
    Visit our tracking page to see a map showing Bertha’s progress. Look for another update this evening.
     
    Barging resumes
     
    As we reported last week, WSDOT has lifted the suspension for cause that halted Seattle Tunnel Partners’ barging operation in January. On Sunday night, crews shifted from trucking away excavated material to removing it by barge. Learn more about STP’s barging operation in this post.
     
    Morning commute recap
     
    Highways:
     
    As expected, this morning’s commute on I-5 started earlier than normal. The heaviest congestion was seen by northbound drivers heading into Seattle with travel times of about 54 minutes from SeaTac.
     
    Seattle surface streets:
     
    Many drivers are using surface streets coming from the south end, with heavy traffic on First Avenue South and Fourth Avenue South. Increased restrictions to street parking helped keep drivers and bus riders moving better this morning than during Friday morning’s commute.  
     
    King County Water Taxi delivering record-level service during Viaduct closure
     
    People across the region continue to shift how they commute to avoid peak congestion during the #99closure, and King County Water Taxi is seeing much higher ridership as a result. Boats to and from West Seattle carried more than 7,700 riders during the past three days, more than tripling typical ridership – and there’s still some capacity and parking as travelers consider their commute options for the remainder of the week.
     
    Information is posted online about expanded West Seattle parking options and regular sailing times during the 99 closure. West Seattle parking is available along Harbor Avenue Southwest, Southwest Bronson Street and at Pier 2 with connecting shuttles. There also is regular shuttle service between the dock and the community.
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  • May 1 #99closure update

    Tunneling progress
     
    Welcome to day three of the #99closure. After a slow and deliberate departure from the planned maintenance stop near Yesler Way, Seattle Tunnel Partners’ tunneling crews picked up speed in accordance with their plan for tunneling under the viaduct. As of 2 p.m. Sunday, Bertha, the SR 99 tunneling machine, had mined 39 feet of the approximately 385 feet of tunnel that must be completed before the viaduct reopens to traffic. STP determines the appropriate rate to mine safely and mining rates will vary as the machine passes underneath the viaduct. 
     
    Visit our tracking page to see a map showing Bertha’s progress.
     
    Traffic overview
     
    Expect a more challenging commute Monday since Mondays are a traditionally heavier traffic day than Fridays. Go to our maps and resources page or see our travel alternatives handout to explore options other than driving. WSDOT continues to run a 24-hour-per-day command center with constant, real-time communication taking place with other agencies. And WSDOT’s Transportation Management Center also has extended hours with up to 12 additional Incident Response Teams ready to clear state roads of incidents as quickly as possible.
     
    The Seattle Traffic Operations Center examined Friday’s commute and is adjusting by extending parking restrictions on Fourth Avenue South from peak periods only to all-day restrictions to help transit and traffic flow. In addition, the Seattle Department of Transportation added protected left turn signals at First Avenue South and South Hanford Street as well as First Avenue South and South Horton Street to improve traffic flow. 
     
    SDOT will continue to work with the Seattle Police Department to monitor and adjust signals as necessary to maximize flow.
     
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  • April 30 #99closure update

    Update 4/30/16 4:00 p.m. STP crews are tunneling slowly and deliberately.

    Tunneling progress

    After completing the first ring, STP crews have been preparing the machine to move out of the concrete of the maintenance stop. The transition from concrete into soil is an important part of tunneling under the viaduct and STP crews have been working to ensure that the transition goes smoothly. Once the machine is fully prepared to mine through this transition, crews will advance slowly and deliberately.

    Big events this weekend

    Commuters will have the weekend to recharge after Friday’s tough commute. Still, travelers should expect significant congestion in the Seattle area on Saturday with both the Sounders and Mariners playing home games. First pitch for the Mariners game is at 7:10 p.m., one hour later than originally scheduled.

    Sounder train service will be running tomorrow to help fans reach the Sunday Mariners game. Visit Sound Transit’s website for schedules and details.

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  • April 29 #99closure update 2

    Tunneling progress
     
    As of 6 p.m. Friday, Bertha, the SR 99 tunneling machine, had dug 6.5 feet of the approximately 385 feet of tunnel that must be completed before the Alaskan Way Viaduct reopens to traffic. This pace is what we expected. The machine will proceed slowly and deliberately throughout the first few days. Visit our tracking page to see a map showing Bertha’s progress.
     
    Bertha must dig through a few more feet of concrete to exit the maintenance stop before she starts to dig through the soil near the intersection of Yesler and Alaskan Way. Look for another progress update Saturday afternoon. 
     
    Afternoon commute overview
     
    The afternoon commute started earlier, was heavier and is on track to end later than a normal Friday. The longest viaduct-related backup we saw was nine miles on southbound I-5 from Shoreline to downtown Seattle. At peak congestion around 4 p.m., it took about 70 minutes to get from Lynnwood to Seattle. Congestion on alternate routes however, including 15th Avenue Northwest, SR 99 and Lake City Way have remained fairly light throughout the commute. Northbound I-5 was clear throughout the commute into downtown Seattle and unusually light from Seattle to Lynnwood for Friday. 
     
    West Seattle and Seattle surface streets
     
    Congestion on alternate routes, however, including 15th Avenue Northwest, SR 99 and Lake City Way remained fairly light throughout the commute. Traffic was extremely congested in SODO because of the Mariners game and due to a malfunctioning railroad arm on South Lander Street.
     
    Plan ahead for a busy Saturday at Seattle’s stadiums
     
    A Sounders match at 1 p.m. and a Mariners game at 7:10 p.m. may test fans heading to the stadiums in SODO. Fans should allow extra time for their trips and consider carpooling, transit, biking and walking to avoid the congestion 
     
    Stay connected
     
    We encourage you to visit our website often and follow @WSDOT_Traffic and @BerthaDigsSR99 as the closure continues. We’ll be posting regular updates about traffic conditions and tunneling progress. Thanks again for your patience as STP works to complete this important phase of the tunnel project.
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  • April 29 #99closure update

    Tunneling progress

    Welcome to day one of the #99closure. Seattle Tunnel Partners began tunneling around 9 a.m. Bertha must first dig through approximately 10 feet of concrete to exit the maintenance stop before she starts to dig through the soil near the intersection of Yesler and Alaskan Way.

    Crews are working around the clock to tunnel, build rings and perform ongoing machine maintenance. The machine will proceed at a slow and deliberate pace throughout the first few days. This evening, our tracking page will have an update showing Bertha’s progress.

    Morning commute overview

    The morning I-5 commute heading into Seattle was heavier than normal for a Friday – it looked more like a Monday morning commute. The northbound I-5 drive into Seattle peaked with a 6-mile backup between 7 a.m. – 10 a.m.

    West Seattle and Seattle surface streets
    First Avenue South and Fourth Avenue South experienced heavier than normal traffic. Drivers and bus riders on Fourth Avenue South between South Spokane and South Washington streets also experienced delays. The West Seattle Water Taxi reported substantially higher ridership than a typical Friday morning.

    Plan ahead for evening commute

    Friday afternoon traffic is normally heavy and with the #99closure, you should expect an even longer drive home. Drivers will see extra traffic on I-5, I-405 and local city streets.

    Mariners fans: The Mariners play the Royals tonight at 7:10. Allow extra time to get there. Carpooling, transit, biking, and walking are all ways to avoid the expected congestion.

    Stay connected

    We encourageyou to visit our website often and follow @WSDOT_Traffic and @BerthaDigsSR99 as the closure continues. We’ll be posting frequent updates about traffic conditions and tunneling progress. Thanks again for your patience as STP works to complete this important phase of the tunnel project.

    Last updated: 12:27 p.m.

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  • #99closure begins: Alaskan Way Viaduct closed for approximately two weeks

    After much planning and anticipation, the approximately two-week closure of the SR 99 Alaskan Way Viaduct is now underway.
     
    Crews closed SR 99 between South Spokane Street and the south end of the Battery Street Tunnel just after midnight Friday, setting the stage for the SR 99 tunneling machine's passage beneath the viaduct. 
     
    Our closure page is your go-to place for all things #99closure. There you’ll find maps, commuting tips and other resources designed to help you get through the closure. 
     
    More than 90,000 vehicles use the viaduct each day. Those folks will now be forced to find other routes to their destination, resulting in congestion that will affect nearby surface streets and other commuting routes throughout the Seattle area and beyond. 
     
    Expect traffic conditions to be tough. Make a plan and check conditions before you head out on the road. We know this closure will be a challenge for everyone, and we appreciate your patience and help in keeping traffic moving. 
     
    Seattle Tunnel Partners tunneling operations
    Seattle Tunnel Partners is making final preparations for their tunnel drive beneath the viaduct. They have told us that the overnight crew will spend the early hours of Friday restarting and testing Bertha, the SR 99 tunneling machine. Tunneling is expected to begin sometime during the day shift on Friday.
     
    STP expects to start slowly as Bertha digs out of her planned maintenance stop, which is essentially a block of concrete buried in the ground near Yesler Way. The machine must dig through approximately 10 feet of concrete to exit the maintenance stop and enter the soil near the intersection of Yesler and Alaskan Way. Initially, trucks will carry away the excavated material. Crews intend to proceed deliberately throughout the weekend, carefully monitoring  the machine’s performance and the surrounding ground as Bertha inches forward.
     
    STP expects to pick up speed early next week. The tunneling operation -- tunneling forward, building rings and doing maintenance on the machine -- will continue around the clock throughout the closure. 
     
    You can track Bertha’s tunneling progress here. We’ll be updating the progress graphic twice each day.
     
    Barging operations to resume
    The suspension for cause that has restricted barging operations since January was lifted this week. That means that STP will be allowed to remove excavated soil from the work site via barge using new procedures they developed over the past two months. Having the barging operation back online allows STP to remove excavated material more quickly than trucking the material offsite.  
     
    Check out our construction cameras page to get a closer look at the barging operation when tunneling begins on Friday.
     
    Stay connected
    We encourage you to visit our website often and follow @WSDOT_Traffic and @BerthaDigsSR99 as the closure continues. We’ll be posting frequent updates about traffic conditions and tunneling progress. Thanks again for your patience as STP works to complete this important phase of the tunnel project.
     
     
    This post was originally published at 1:11 p.m. on April 28. It was updated at 12:15 a.m. on April 29 to reflect the start of the closure.  
     
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  • Preparing for the #99closure

    Seattle-area roadways will be a major challenge starting this Friday, April 29, when the Alaskan Way Viaduct closes for approximately two weeks. The closure will give our contractor, Seattle Tunnel Partners, the time they needs to tunnel beneath the viaduct. It will give drivers a reminder of what its like to live without one of three major north-south highways through Seattle. 
     
    We put together a series of short videos to help you get ready for the closure. The videos cover a variety of topics ranging from alternative commute methods to tools that will help you stay informed. Theres no easy solution for getting around during the closure, but planning ahead is your best bet for avoiding the worst congestion. 
     
    We hope the videos will help jumpstart your planning. We also encourage you to share tips and tricks with fellow commuters. Join the conversation by using the hashtag #99closure on social media. 


    Know before you go
    This is your "survival guide" for getting around during the #99closure. Learn about the tools that are available at our closure page. Find us on Facebook and Twitter, and consider downloading the WSDOT and SDOT apps. 

    Learning from the 2011 closure
    Does the #99closure feel like Déjà vu? If so, it may be because we closed the viaduct in 2011 for one week as crews tore down the southern mile of the structure. You might also remember the heavy congestion that occurred while the viaduct was closed. Expect more of the same this time around. Why? Since 2011, weve seen tremendous population growth in the area. That means more cars on the road.

    The good news is that transportation infrastructure has improved some since then. The City of Seattle opened a new streetcar line, WSDOT opened the South Atlantic Street Overpass by the stadiums and Sound Transit last month opened University Link

     

    Adjusting your commute
    Its not too late to adjust the way you commute. Vanpools, biking, taking a ferry and riding the bus are just a handful of options available for those able to do so. Weve teamed up with our partner agencies to help move people during the #99closure:
     
    Transit
     
    City Streets
    • Seattle Police Department will direct traffic at key intersections.
    • Temporary parking restrictions along key routes will facilitate transit and general purpose travel.
    • SDOT is expediting planned intersection markings along East Marginal Way South to assist bicycle and pedestrian routes.
    • Traffic flow and temporary parking changes will help get vehicles on and off Aurora at Denny Way, Wall Street and Battery Street.
    • SDOT is restricting lane closure requests by third parties on city streets.
     
    Highways
    • I-5 express lanes will remain open in the northbound direction overnight.
    • Southbound I-5 HOV lane between Mercer Street and Corson Avenue will be "open to all" during the closure.

     

    Stay plugged in
    Cant avoid driving during the #99closure? Make sure to plan ahead before hitting the streets. Here are some tools you can use to make your commute as painless as possible.
     
     
    Avoiding traffic
    Peak commute times will likely be longer than usual during the #99closure. We expect congestion to start earlier and end later in the day. For those who can, nows a great time to consider working from home, taking a vacation or changing your work hours. Many employers allow it, and the earlier you ask the better. Itll save you time, plus fewer cars on the road is better for everyone. 
     
     
    We understand the major inconveniences caused by closing a portion of SR 99. Like you, we're looking forward to completing this part of the project so the viaduct can reopen and the tunnel team can continue on its way beneath downtown. Until then, thanks for your patience and assistance in helping your fellow travelers through the closure.

     

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  • SR 99 closure video #1: Know before you go

    You’ve probably heard that on Friday, April 29, the Alaskan Way Viaduct will close for two weeks while the SR 99 tunneling machine, Bertha, tunnels underneath the structure near the intersection of Yesler Way and Alaskan Way in Seattle. We know closing the viaduct is a major inconvenience for commuters, and we expect that traffic will be tough. 
     
    This week we’ll be sharing a series of short videos to help folks prepare. Consider this first installment your “survival guide” for getting around during the #99closure. 
     
     
    Don't forget that 99closure.org is the best source for the most up-to-date information about the #99 closure.
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  • Work continues on SR 99/Aurora Avenue North through April

    Drivers should expect two more weeks of full weeknight closures on State Route 99/Aurora Avenue North. After completing electrical work, crews will now be installing large supports for overhead highway signs that will help direct future traffic to the SR 99 tunnel. 
     
    Closure details
     
    Monday, April 18 – Thursday, April 21 and Monday, April 25 – Thursday, April 28 
    • Crews will close all lanes of southbound SR 99/Aurora Avenue North from just south of the Aurora Bridge to Thomas Street from 10 p.m. to 5 a.m. 
    • On Monday, April 18, southbound traffic will be detoured to Raye Street. All other days, traffic will be detoured to exit to Dexter Avenue North.
    • Local access will be maintained. 
    • Crews will also close the left lane of northbound SR 99 between Valley and Raye streets from 7 p.m. to 5 a.m.
     
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  • April 15 project update: Hedges named new program administrator

    Following an extensive nationwide search, the Washington State Department of Transportation has selected Joseph Hedges to be the next administrator of the Alaskan Way Viaduct Replacement Program.
     
    Hedges has 30 years of experience in program management, large-scale construction and engineering design in both the public and private sectors. That includes extensive experience with complex and high-profile projects as well as design-build contracts like the one WSDOT is using to administer the SR 99 Tunnel Project. Hedges has led large quality assurance and quality control programs, and has developed integrated risk management programs that include quality, safety and environmental protection. He is also accustomed to working on controversial projects, including overseeing the disposal design of the nation’s oldest nuclear inventory.
     
    He most recently served as executive vice president and director of operations for Coastal Environmental Group, a New York firm specializing in construction, environmental remediation, energy efficiency and disaster response. Prior to that Hedges was the chief engineer for Pro2Serve, of Oak Ridge, Tennessee, where he led a multidisciplinary team of more than 150 engineers and designers. Other career highlights include serving as assistant chief of staff overseeing $1.2 billion of complex military construction projects as a Navy officer in Iraq, and managing disaster relief efforts following Hurricane Sandy. 
     
    “The SR 99 tunnel will transform Seattle’s waterfront and the corridor, and I am grateful for the opportunity to be a part of such a historic project,” Hedges said. “I look forward to joining the outstanding people at the Washington State Department of Transportation in their ongoing work to replace the Alaskan Way Viaduct.”
     
    In joining the viaduct program, Hedges takes over one of the largest construction efforts in state history. The $3.1 billion program includes more than 30 projects, among them the SR 99 tunnel that is currently under construction beneath Seattle.
     
    Hedges will join the program in late April where he will initially work alongside current Administrator Todd Trepanier. Trepanier, who lives in Yakima and assumed leadership of the viaduct program in summer 2013, was named administrator of WSDOT’s South Central Region last summer. He is expected to transition to that role later this spring.
     
    Joseph Hedges
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  • Mark your calendars: Alaskan Way Viaduct closes for approximately two weeks starting April 29

    Updated April 26 to include closure times

    Drivers and transit users, pay heed: there are 14 days to get ready for a closure of the State Route 99 Alaskan Way Viaduct through downtown Seattle. Starting Friday, April 29, the Washington State Department of Transportation will close the viaduct between South Spokane Street and the south end of the Battery Street Tunnel.
     
    The closure will beging at 12:01 a.m. on Friday, April 29. Crews will begin closing on-ramps to the viaduct at 10 p.m. on Thursday, April 28.
     
    Roughly 90,000 vehicles use the viaduct each day. Because the structure is one of three major north/south highways in the greater Seattle area, WSDOT expects this closure to have a significant effect on the region’s commute. 
     
    “When we closed the viaduct for nine days in 2011, we saw significant congestion on Seattle city streets and nearby highways,” said David Sowers, deputy administrator of the Alaskan Way Viaduct Replacement Program. “We’ll do everything we can to ease congestion, but unfortunately there’s no way to close a major highway without disrupting traffic.”
     
    WSDOT, the Seattle Department of Transportation, King County, the Port of Seattle and other agencies around Puget Sound have joined forces to help drivers and commuters plan for the closure and change their normal routines. A website dedicated to the closure – www.99closure.org – lists resources and ideas on ways to adjust commutes and work schedules. 
     
    “We understand this closure will be a major inconvenience for many drivers, but we need their help to keep traffic moving,” said Sowers.  “We will all get through this together if everyone starts the planning process now and adjusts their commutes.” 
     
    WSDOT is working with partner agencies to provide standby buses, more real-time traffic monitoring, police officers at key intersections to keep traffic moving, additional water taxi capacity, additional response vehicles to clear accidents quickly and more.   
     
    Some options for commuters to consider
     
    • New ways to commute: The recently opened Sound Transit University Link Extension can take commuters from the University District to downtown in eight minutes. In addition, Seattle’s new First Hill Streetcar can carry more commuters to downtown. 
    • Alternatives to driving: Take the bus with King County Metro. Share a ride in a carpool, vanpool or van share. Explore other transit options using the Puget Sound Trip Planner. Remember that while taking transit is a great alternative to driving, buses are expected to be crowded during the closure.
    • Take the water taxi: King County Water Taxi is adding extra trips to and from Vashon Island to Colman Dock. There will be additional parking in West Seattle for the water taxi’s new, larger-capacity boat.
    • Work from home: Many employers offer options to work from home. Even teleworking one day a week will help ease congestion. 
    • Adjust the work schedule: If possible, adjusting a work schedule can help avoid the longer commutes. Rush hours will start earlier and end later than normal. Use WSDOT's travel tools or SDOT’s traveler information page to plan your trips. 
    • Consider biking or walking for the last part of a trip into downtown to avoid the heaviest congestion.
     
    Closing the viaduct during tunneling will enable better monitoring of the structure and allow for quick repairs if any ground movement from tunneling should occur.
     
    In addition to strengthening measures taken by WSDOT over the years, the SR 99 Tunnel contract also directed Seattle Tunnel Partners to protect the viaduct during tunneling. The video below shows how the viaduct has been strengthened and protected.
     
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  • April 11 project update: Tool replacement complete

    Seattle Tunnel Partners has now completed nearly 100 shifts of hyperbaric work inside the SR 99 tunneling machine. One of their biggest tasks – inspecting and replacing cutting tools on the machine’s face – is now complete.
     
    Cutting tools are expected to wear down over time, and replacing them is a normal part of tunneling. Because most of the machine’s tools were replaced during the repair effort, STP chose to replace only 11 of the more than 700 tools they inspected in the weeks since the machine reached its planned maintenance stop near Yesler Way. 
     
    STP still has some routine maintenance left to complete. They have told us that the machine is functioning as intended and will soon be ready to tunnel beneath the Alaskan Way Viaduct. WSDOT will close the viaduct for approximately two weeks to allow the machine to pass beneath the structure. We will provide the public with advance notice of the closure, but the start date isn’t yet known. It will depend on how long the remaining maintenance takes to complete. 
     
    Although the closure date hasn’t been set, it’s not too early to start thinking about your commute options. Our closure page, www.99closure.org, includes maps, commute tips, information about transit reroutes and answers to frequently asked questions. We’ll continue to add information to this page in the coming weeks.
     

     

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  • Overnight closures of SR 99 start April 4

    Drivers should expect full weeknight closures in one direction of State Route 99/Aurora Avenue North during the next three weeks just north of downtown Seattle.
     
    During the closures, crews working for Atkinson Construction will close one direction of the highway to install street lights, traffic sensors and sign bridges. The closures are part of ongoing work to build the roadway and ramp connections between Aurora Avenue North and the north portal of the SR 99 tunnel. 
     
    Closure details
    • Monday, April 4, to the morning of Friday, April 8: Crews will close all lanes of northbound SR 99/Aurora Avenue each night from 10 p.m. to 5 a.m. from the south end of the Battery Street Tunnel to Valley Street. 
    • Monday, April 11, to the morning of Saturday, April 16: Crews will close all lanes of southbound SR 99/Aurora Avenue North each night from 10 p.m. to 5 a.m. from Valley to Thomas streets.
    • Monday, April 18, to the morning of Tuesday, April 19: Crews will close all lanes of southbound SR 99/Aurora Avenue North from the Fremont Way North on-ramp to the south end of the Battery Street Tunnel from 10 p.m. to 5 a.m. Crews will also close the left lane on northbound SR 99 between Mercer Street and the south end of the Aurora Bridge from 7 p.m. to 5 a.m.
    • Tuesday, April 19, to the morning of Friday, April 22: Crews will close all lanes of southbound SR 99/Aurora Avenue North just south of the Dexter Avenue North exit to the south end of the Battery Street Tunnel from 10 p.m. to 5 a.m. Crews will also close the left lane on northbound SR 99/Aurora Avenue North between Mercer Street and the south end of the Aurora Bridge each night from 7 p.m. to 5 a.m.
     
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  • April 1 project update: Inspections and maintenance continue

    Seattle Tunnel Partners has now completed more than 60 shifts of hyperbaric work inside the space behind the cutterhead of the SR 99 tunneling machine. Inspections and maintenance have been ongoing since the machine reached a planned maintenance stop last month. Crews have spent most of their time cleaning muck from the cutterhead openings and spokes, measuring and assessing cutting tools, and replacing them where necessary. 

    As this previous post explains, hyperbaric conditions are those in which the pressure is greater than the atmosphere we live and breathe in every day. Crews must undergo a rigorous physical examination and training prior to working in hyperbaric conditions. Working in these conditions requires them to first slowly adjust their bodies to the pressure, similar to what scuba divers must do to safely complete an underwater dive. This adjustment takes place in a pressurization chamber located within the machine. 

    Crews spend up to one hour in the pressurization chamber (shown in the photo below) prior to going to work in the space behind the cutterhead. When the pressure in the chamber matches the pressure in the space behind the cutterhead where they’ll be working, crews can enter through small hatches.

    Hyperbaric chamber

    Five crew members at a time work in the space behind the cutterhead. At the current working pressures, they can safely spend between 1 to 2 hours working before returning to a decompression chamber to readjust their bodies to normal pressure. Decompression takes up to 90 minutes. Crews can only complete one shift of hyperbaric work per day. It’s hard work in tight quarters, as the short video provided by STP illustrates.

    When STP’s maintenance is complete, they will begin tunneling beneath the Alaskan Way Viaduct. WSDOT will close the viaduct for approximately two weeks during this section of the tunnel drive. We will provide the public with advance notice of the closure, but the start date isn’t yet known. It will depend on the amount of work that must be completed while the machine is in the maintenance stop. Check www.99closure.org for additional details as the closure approaches.

    Recent updates 

     
    For earlier program updates, please visit our archive page.
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  • March 23 project update: Machine inspections underway

    Inspections and routine maintenance of the SR 99 tunneling machine are ongoing as Seattle Tunnel Partners continues preparing the machine for its drive beneath the Alaskan Way Viaduct.
     
    Crews have been performing planned maintenance since the machine reached a maintenance stop earlier this month. They’ve also been preparing for a series of inspections that must occur in hyperbaric conditions. Hyperbaric conditions are those in which the air pressure is greater than the atmosphere we live and breathe in every day – similar to what scuba divers experience during the course of an underwater dive. This post explains the process for completing hyperbaric work.
     
    So far this week, STP crews have completed a total of 10 hyperbaric shifts in the chamber behind the tunneling machine’s cutterhead. Most of that time has been devoted to cleaning muck from the cutterhead openings and building the platforms crews will stand on as they perform the inspections. 
     
    The inspections are expected to take several more days. STP will determine the expected duration of the remaining maintenance based on the results of the inspections.
     
    The end of the maintenance period will usher in the next step in Bertha’s journey: a trip beneath the viaduct. WSDOT plans to close the viaduct for approximately two weeks to allow the machine to pass beneath the structure. 
     
    We will provide the public with advance notice of the closure, but the start date isn’t yet known. It will depend on the amount of work that must be completed while the machine is in the maintenance stop. Check www.99closure.org for additional details as the closure approaches.
     
    Recent updates 
     
    For earlier program updates, please visit our archive page.
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  • March 14 project update: Bertha reaches planned maintenance stop

    On Saturday, Bertha, the SR 99 tunneling machine, reached a planned maintenance stop near Yesler Way after successfully mining almost 300 feet during the past three weeks. According to Seattle Tunnel Partners, the machine functioned within required operating parameters. STP has now mined a total of 1,560 feet. 

    STP will spend up to one month inspecting the machine and performing planned maintenance. Scheduled work includes:
    • Performing hyperbaric interventions
    • Inspecting the cutterhead, main drive unit and screw conveyor
    • Replacing cutting tools
    • Extending the conveyor belt and the high-voltage cable 
     
    When STP has completed its maintenance work, crews will tunnel out of the maintenance stop and beneath the Alaskan Way Viaduct. WSDOT plans to close the viaduct for approximately two weeks to allow the machine to pass beneath the structure. 
     
    We will provide the public with advance notice of the closure, but the start date isn’t yet known. It will depend on the amount of work that must be completed while the machine is in the maintenance stop. STP won’t know the extent of the needed maintenance until inspections are complete, a process that could take approximately two weeks of the one-month maintenance period. Check www.99closure.org for additional details as the closure approaches.
     
    A closer look at Bertha’s planned maintenance stop
    The maintenance stop – sometimes referred to as Safe Haven 3 – is essentially a solid concrete block built underground near Yesler Way. Being in concrete, rather than unprotected ground, allows STP to perform maintenance more easily. This is because the concrete provides a stable environment around the machine as crews work in hyperbaric conditions within the excavation chamber behind the cutterhead. 
     
    Maintenance stop rendering
     
    Bertha's planned maintenance stop is located more than 60 feet underground, approximately 450 feet north of the access pit and 40 feet west of the viaduct. 
     
    Construction of Bertha's planned maintenance stop in 2013
     
    Crews inject grout into the ground in 2013 during construction of Bertha’s planned maintenance stop.
     
    Recent updates 
     
    For earlier program updates, please visit our archive page.
     
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  • March 7 project update: Demonstration period complete, mining continues

    WSDOT on Monday notified Seattle Tunnel Partners that they could continue mining to a planned maintenance stop near Yesler Way. The notification came as STP completed the 25-ring demonstration period that was put in place when mining resumed on Feb. 23.
     
    The underground maintenance stop is approximately 120 feet north of the tunneling machine’s current location near South Washington Street. The machine has traveled a total of 1,437 feet and the bored section of the SR 99 tunnel is now 15 percent complete.
     
    STP will continue to operate using the changes and commitments that were put into effect during the conditional lift.
     
    Barging still suspended
    While mining is ongoing, barging activities are still restricted pending submittal of additional documentation. STP is removing excavated soil by truck as they continue addressing the barging issue. Repairs to the pier that was damaged during the Jan. 12 barging incident were completed last month.
     

     

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  • March 3 project update: Bertha tunneling toward South Washington Street

    Bertha, the SR 99 tunneling machine, has traveled approximately 110 feet since Seattle Tunnel Partners resumed mining on Feb. 23. The machine has tunneled a total of 1,391 feet and is approaching South Washington Street.
     
    STP is now 17 concrete rings into the 25-ring demonstration period that was put in place when WSDOT conditionally lifted the Jan. 14 suspension for cause. Crews are mining north to a planned maintenance stop just south of Yesler Way. Once there, they could spend several weeks performing final maintenance before the machine tunnels beneath the Alaskan Way Viaduct. 
     
    Update on barging
    While mining is ongoing, barging activities are still restricted pending submittal of additional documentation. STP is removing excavated soil by truck as they continue addressing the barging issue. Repairs to the pier that was damaged during the Jan. 12 barging incident were completed last month.
     

     

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  • Sign foundation work on SR 99/Aurora Avenue North complete (for now)

    Crews have finished installing concrete foundations for new overhead traffic signs on SR 99/Aurora Avenue North. Located between the Aurora Bridge and just north of Mercer Street, these traffic signs will communicate important information to drivers approaching the future SR 99 tunnel – similar to the large signs on I-5 and other highways. 
     
    Crews finished foundation work near Comstock Street on Tuesday morning, March 1. The project began in mid-January and required lane reductions along this section of Aurora. Thank you for your patience and flexibility as we completed this work. 
     
    Minor electrical work continues 
    Electrical crews will continue working for one to two more weeks to install underground electrical cabinets and connect communications lines to the overhead system. This work will continue to intermittently close one southbound lane at Valley Street and Raye Street during off-peak hours only.
     
    Future lane closures on SR 99 
    This spring crews will return to SR 99 to erect the metal sign structures at each of the new foundations (the actual signs will be hung at a later date). Because of the size of the structures and the equipment needed, this work will require partial or full directional closures on SR 99. We will notify the traveling public of expected traffic impacts once this work is scheduled. 
     
    Questions? 
    For questions or concerns about SR 99 lane closures, contact us at viaduct@wsdot.wa.gov or 1-888-AWV-LINE (298-5463). 
     
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  • Feb. 26 project update: Mining continues

    Bertha, the SR 99 tunneling machine, has mined 25 feet and built three concrete tunnel rings since mining resumed on Tuesday. At the time of this post, crews were installing the fourth ring.
     
    Crews took a break from mining on Thursday to stabilize the ground behind the machine. Grout was injected above a section of the tunnel that was mined before WSDOT ordered the Jan. 14 suspension for cause. Mining was ongoing on Friday and was scheduled to continue through Saturday, according to STP. Crews will take Sunday off and mine again next week. 
     
    As part of the conditions for lifting the suspension for cause, STP has been permitted to tunnel forward and install approximately 25 concrete tunnel rings. During this time, they must demonstrate that they have implemented a number of changes to ensure they can safely continue mining. Details of the changes are included in this post.
     
    We’ll continue to provide updates as STP’s work progresses.
     

     

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  • Viaduct inspection closure set for this weekend, March 5 and 6

    Post updated March 5 at 5:30 p.m. 

    UPDATE 5:30 P.M. MARCH 5: The semiannual inspection of the State Route 99 Alaskan Way Viaduct is now complete and the viaduct is open to traffic for the rest of the weekend. 

    Drivers should be aware that the annual Hot Chocolate 15k/5k Run will close SR 99/Aurora Avenue North Sunday morning, March 6 from 6 a.m. to noon. The closure starts at the south end of the Battery Street Tunnel and ends just south of the Woodland Park Zoo. 
     

    March is here, which means it’s time for the semiannual inspection of the Alaskan Way Viaduct. On March 5 and 6, WSDOT bridge inspectors will close the viaduct so they can inspect the roadway. While the viaduct is frequently monitored, these twice-yearly inspections require a weekend closure so crews can scrutinize the bridge. During the closure they will measure existing cracks and look for new ones. They will also check for structural movement and examine the viaduct’s foundations.

    Both directions of the Alaskan Way Viaduct will close between South Spokane Street and the north end of the Battery Street Tunnel on both Saturday, March 5 and Sunday, March 6. Drivers should plan ahead and be prepared for additional congestion as a result of these closures.
     
    In addition to the inspection closure, the annual Hot Chocolate 15k/5k Run will require a closure of SR 99/Aurora Avenue North on Sunday morning, March 6. 
     

    Closure Details

    Alaskan Way Viaduct inspection closure
    6 a.m. to 6 p.m. both Saturday, March 5, and Sunday, March 6
    • The Alaskan Way Viaduct will be closed between South Spokane Street and the north end of the Battery Street Tunnel.
     
    Hot Chocolate Run closure
    6 a.m. to noon, Sunday, March 6
    • SR 99/Aurora Avenue North will close in both directions.
    • Northbound lanes will be closed between the Battery Street Tunnel and North 47th Street. 
    • Southbound lanes will be closed between the Battery Street Tunnel and North 38th Street.
     
    Note to Sounders fans
    The Sounders have a match at 4 p.m. this Sunday. WSDOT bridge inspection crews will work to reopen the viaduct as soon as possible, but there is a possibility it could remain closed until 6 p.m. Sounders fans headed to the game should stay engaged, have backup plan and check WSDOT’s Seattle Area Traffic webpage before they leave home.  
     
    You can also check the Seattle Department of Transportation’s traveler information page for updated information on the closure as well as WSDOT’s travel tools for information about traffic in the Puget Sound region.
     
    More about viaduct safety
    Read our viaduct safety fact sheet (pdf 2.9 Mb) to learn more about what we do to keep the viaduct safe and open to drivers until the tunnel project is complete.  
     
    Viaduct inspection
    Survey crews walk the viaduct during a previous inspection.

     

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  • Feb. 23 project update: Seattle Tunnel Partners resumes mining

    Seattle Tunnel Partners has received conditional permission to resume tunneling operations on the SR 99 Tunnel Project. STP resumed mining today after WSDOT conditionally lifted the “suspension for cause” that halted mining and barging-related activities last month following two safety incidents. 
     
    As part of the conditions for lifting the suspension for cause, STP will be permitted to tunnel forward and install approximately 25 concrete tunnel rings. During this time, they must demonstrate that they have implemented a number of changes to ensure they can safely continue mining. These changes include:
     
    • Updated tunnel work and quality plans, including calculations of the amount of soil removed during excavation of each tunnel ring.
    • Realignment of key personnel within their quality assurance program.
    • New quality assurance protocols.
    • New personnel at key positions within the tunneling operation.
    • Restructured daily tunneling meetings that include additional participants and protocols.   
     
    WSDOT made the decision to conditionally lift the suspension for cause after its team of tunneling experts evaluated documentation submitted by STP over the past several weeks. While mining can resume, barging activities are still restricted pending submittal of additional documentation. STP will remove excavated soil by truck as they continue addressing the barging issue. Repairs to the pier that was damaged during the Jan. 12 barging incident were completed earlier this month.  
     
    Work was suspended for cause on Jan. 14 per section 14.2 of the contract, which says the state can suspend work without liability to WSDOT under a number of conditions, including the contractor’s failure to “correct conditions unsafe for the project personnel or general public.” 
     
    The suspension for cause only addressed tunneling operations involving the tunneling machine and the loading of barges at the site. It did not apply to the other ongoing work under the design-build contract with STP or any other contracts being managed by the viaduct program.
     
    After the suspension for cause was put in place, WSDOT notified STP that they would need to confirm the following things before mining could resume:
     
    • The tunneling machine is operating as intended and meets the design-build contract’s technical requirements.
    • All necessary training for staff on the tunneling machine is complete.
    • The tunneling work plan is updated to address the over-excavation that led to the sinkhole.
    • Processes are in place to ensure STP’s tunneling work plan is followed.
    • STP updates its quality program to ensure key quality program managers are involved in all tunneling activities.
     
    Next steps
     
    The tunneling machine is currently located west of the Alaskan Way Viaduct, near South Washington Street. The conditional lift will remain in place for approximately 160 feet of tunneling. During this period – which is considered part of STP’s initial testing phase – STP will be operating with additional communication with WSDOT and its tunneling experts. If STP demonstrates that their revised mining procedures are effective, crews will continue mining an additional 100 feet north to a planned maintenance stop. Once there, crews could spend several weeks performing final maintenance before the machine tunnels beneath the Alaskan Way Viaduct. 
     
    WSDOT will fully close SR 99 through downtown for approximately two weeks while the machine passes beneath the viaduct. The closure date will depend on the tunneling machine’s progress. Check www.99closure.org as the closure approaches for additional details. 
     
    Statement from Gov. Jay Inslee 
     
    “WSDOT, in consultation with its team of tunnel experts, lifted the suspension of tunneling for cause and said that conditional tunneling should resume for 25 more tunnel rings. I concur with their decision, and WSDOT has notified the contractor,” said Inslee. 
     
    “The contractor has a plan for modifying tunnel operations to ensure positive ground control. It has also made changes to key personnel, and it has put in place protocols for quality control and assurance. The contractor now has an opportunity to show progress during this test period, prior to tunneling under the viaduct and underneath Seattle,” he said.
     
    Statement from Acting Transportation Secretary Roger Millar:
     
    “Seattle Tunnel Partners has addressed the issues that led to the suspension for cause. This conditional lift of the suspension for cause will give STP an opportunity to demonstrate the effectiveness of their updated mining procedures,” said Millar. 
     
    “Above all else, this project has always been about safety. We must continue our work to replace the viaduct, but we have an obligation to ensure that work proceeds safely. We will continue to work with STP while taking whatever steps are necessary to protect the interests of the public moving forward,” he said.
     
    Recent updates 
     
    For earlier program updates, please visit our archive page.
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  • Lane closures on SR 99/Aurora Avenue North wrapped up early, next phase began Feb. 8

    Contractor crews building the northern approach to the new SR 99 tunnel have been working since Jan. 18 to install foundations for four overhead traffic signs on SR 99/Aurora Avenue North between the Aurora Bridge and just north of Mercer Street. Work progressed ahead of schedule and the first phase of work wrapped up one week early. By Friday afternoon, Feb. 5, the median lanes in both directions reopened and the southbound bus-only lane was restored.

    Crews will be working for two to three more weeks near Comstock Street to install the final sign foundation as part of the second phase of work.

    Lane closure details: 8 p.m. Monday, Feb. 8 to late February

    • The southbound curb/bus-only lane near Comstock Street is closed for approximately one block.
    • An additional southbound lane may close overnight.
    • Buses traveling in the bus-only lane will merge into the general purpose lane a few blocks north of where the bus-only lane currently ends.

     

    Minor electrical work: week of Feb. 8 through early March

    As foundation work near Comstock Street progresses, electrical crews will be installing underground electrical cabinets at the sign foundations, wiring for a new traffic camera and connecting communications lines to the existing overhead system. Electrical work is scheduled to take four to five weeks to complete and will require an intermittent, localized lane closure at specific points along SR 99. These closures will be limited to off-peak hours only (10 a.m. to 2 p.m.) and are not expected to significantly impact traffic. The schedule for electrical work is approximate and may change. We will keep the public informed as work progresses.


    What’s been happening?

    During the first phase of work, crews cut and removed about 1,600 square feet of pavement, drilled four large underground shafts for the sign foundations, installed rebar and poured concrete into the shafts. They also placed new concrete barrier around each of the new foundations for additional protection and support, and began installing underground power and communications lines to support electronic messaging systems related to the future tunnel.   

    Since work began, travel times for cars and buses during peak periods in the morning and afternoon remained fairly steady – not just on SR 99 but on nearby arterials as well. So whether you've been leaving your house or work an hour earlier, riding your bike, or avoiding SR 99 altogether, we appreciate your efforts to help us keep traffic moving.

    Night work

    In an effort to balance the needs of drivers and residents, some work will occur during nighttime hours. An additional southbound lane may close at night to provide extra work space.

    Questions?

    For questions or concerns about SR 99 lane closures, contact us at viaduct@wsdot.wa.gov or 1-888-AWV-LINE (298-5463). 

     

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  • Feb. 5 project update: Seattle Tunnel Partners set to repair damaged pier

    Seattle Tunnel Partners is set to repair damage that occurred at the Port of Seattle's Terminal 46 during the Jan. 12 barging incident. STP will remove 22 damaged timber piles from the pier at the northern edge of Terminal 46 and replace them with temporary piles. Work is expected to begin in the coming days and could take up to 10 days to complete, according to STP. 
     
    WSDOT and STP continue to work together to address the “suspension for cause”  that halted tunneling and barging operations on Jan. 14. STP crews are prepared to remove excavated soil by truck if tunneling resumes before the pier at Terminal 46 is repaired.
     
    You can watch the pier repairs unfold on our construction camera. The labels on the image below call out some of the key elements you’ll see in the regularly updated time-lapse images.
     
     
    Ground monitoring update
    It’s been approximately two weeks since Seattle Tunnel Partners turned off the deep dewatering wells that were used to control groundwater near the access pit. There was some upward ground movement in the days following the shut-off, but the movement quickly stabilized. The degree of movement tapers off over several city blocks and is uniform in nature, which poses little to no risk of damage to the Alaskan Way Viaduct or buildings.    
     
    Some ground survey points in the vicinity of the pit show as much as 3/5 inch of upward movement since Jan. 22 when STP began turning off the wells. Some of the Alaskan Way Viaduct columns and buildings show similar movement. 
     
    STP had additional, shallower dewatering wells in operation during the tunneling machine repair effort. They turned off the final two shallow wells on Thursday evening. STP and WSDOT continue to monitor the ground, buildings, utilities and the viaduct.     
     
    Recent updates 
     
    For earlier program updates, please visit our archive page.
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  • Jan. 28 project update: Suspension for cause still in place

    Last week, Seattle Tunnel Partners submitted their analysis of recent incidents on the SR 99 Tunnel Project. WSDOT and their tunnel experts determined STP’s analysis did not sufficiently address the cause of these incidents or specify how they would prevent them from occurring in the future.
     
    WSDOT has notified the contractor that in order to lift the suspension for cause, STP must confirm that:
     
    • The tunneling machine is operating as intended and meets the design-build contract’s technical requirements.
    • All necessary training for staff on the tunneling machine is complete.
    • The tunneling work plan is updated to address the issues that led to the sinkhole.
    • Processes are in place to ensure STP’s tunneling work plan is followed.
    • STP updates its quality program to ensure key quality program managers are involved in all tunneling activities.
     
    It is STP’s responsibility to determine how to address these issues and ensure they are in compliance with the technical requirements of the contract. This section of the tunnel drive was designed to be a test section for operation of the tunneling machine. With approximately 250 feet of tunneling prior to reaching the next planned maintenance stop, demonstration of these steps is critical.
     
    We will continue to provide updates as new information becomes available.
     

     

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  • Jan. 18 to early March: Extended lane closures on SR 99/Aurora Avenue North

    What's happening 
    Drivers and commuters should plan for increased congestion during construction work that has reduced both directions of SR 99/Aurora Avenue North by one lane between the Aurora Bridge and just north of Mercer Street. Check out our program spotlight for more information on this closure and its timing. 
     
    Closure details - SR 99 between the Aurora Bridge and just north of Mercer Street:
     
    • 8 p.m. Monday, Jan. 18 through mid-February
      • Median lanes close in both directions between the Aurora Bridge and just north of Mercer Street. 
      • An additional lane will close at night and during several weekends including Jan. 23-24. 
      • All traffic may use the southbound bus-only lane during the first phase of this work. Drivers should use caution since buses will travel – and stop – in the outside lane with other vehicle traffic.  

     

    • Mid-February through early March
      • Median lanes reopen. Northbound lanes reopen. 
      • The southbound right lane will be closed near Comstock Street. 
      • An additional southbound lane may close at night.
     

    The schedule for this work is approximate and may change. We will keep the public informed as work progresses.

     
    Animation showing lane closures 
     
     
    Traveler tips
     

    We anticipate additional backups on SR 99 for vehicles and buses, particularly during peak commute times. WSDOT is encouraging drivers and bus riders to:  

     

    Bus rider information

    During the first four to five weeks of work, southbound buses will travel – and stop – in the outside lanes with other vehicle traffic. Trips may take longer than normal so transit riders should allow extra travel time and, if possible, avoid traveling during peak commute times. King County Metro will have additional buses on standby to help maintain transit schedules.

    What's happening?

    Contractor crews building the northern approach to the new SR 99 tunnel will install the foundations for new overhead traffic signs. These signs require sturdy, concrete-encased pedestals along with communication lines, power lines and traffic sensors. Around-the-clock lane closures are necessary for crews to perform the work in a safe and efficient manner. Because of the small work area, some activities may take longer to complete and others can only be completed overnight when a second lane will be closed to provide a larger work zone.

    WSDOT understands that these closures will be inconvenient for those who use SR 99 on a regular basis. As such, this work is being completed in winter when traffic volumes are typically lower and there are fewer special events. 

    Nighttime and weekend work

    In an effort to balance the needs of drivers and residents, some work will occur during nighttime and weekend hours. An additional lane may close at night and during some weekend days, including Jan. 23-24. This will provide additional work space for contractor crews. 

    Questions?

    Contact us at viaduct@wsdot.wa.gov or 1-888-AWV-LINE (298-5463), or visit us at www.AlaskanWayViaduct.org

     

    Originally posted Dec. 7, 2015.

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  • Jan. 21 project update: The path forward

    Last week, WSDOT notified Seattle Tunnel Partners that they must “suspend for cause” tunneling operations involving the tunneling machine and the loading of barges. WSDOT took this step to ensure STP's work can proceed safely following recent incidents on the SR 99 Tunnel Project. Safety remains the top priority for the project and we can’t speculate on when tunneling will resume. 
     
    In response to the suspension for cause, STP has informed WSDOT they are analyzing the recent incidents and intend to provide follow-up information this week. WSDOT, in consultation with its tunneling experts, will then review the information and determine the appropriate next steps. 
     
    STP has notified WSDOT they plan to sequentially turn off the deep dewatering wells soon. These wells, which have been used to control groundwater, were previously scheduled to be shut off when the tunneling machine reaches the next planned maintenance stop. With tunneling operations currently on hold, STP has determined that there is an opportunity to turn off the wells earlier than planned. We will continue to monitor movement of the ground, structures, utilities and the viaduct. Additional information about our ground monitoring program can be found here.
     
    We will continue to provide updates as new information becomes available.
     

     

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  • Jan. 14 project update: Tunneling on hold pending safety review

    In light of recent incidents on the SR 99 Tunnel Project, WSDOT has notified Seattle Tunnel Partners (pdf 372 KB) that they must "suspend for cause" tunneling operations involving the tunneling machine and the loading of barges. 
     
    STP must complete a detailed analysis and modify tunneling operations to ensure appropriate ground control. STP will not be allowed to resume tunneling until their analysis and work plans meet the satisfaction of the design-build contract and WSDOT’s experts.
     
    The tunnel contract contains a few different mechanisms for stopping work. In this case, WSDOT suspended work “for cause” per section 14.2 of the contract, which says the state can suspend work without liability to WSDOT under a number of conditions, including the contractor’s failure to “correct conditions unsafe for the project personnel or general public.”  
     
    This suspension for cause only addresses tunneling operations involving the tunneling machine, including loading of barges at the site. It does not affect any of the other work under the design-build contract with STP or in any other contracts being managed by the viaduct program. For example, the Aurora Avenue North lane closures will occur as scheduled next week. 
     
    Our intent in directing this suspension of work is to ensure the tunneling operation proceeds safely. 
     

     

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  • Jan. 13 project update: The latest on mining and barging

    Seattle Tunnel Partners resumed mining Tuesday evening, using trucks to remove excavated material while they continued working to resolve an issue with a soil-removal barge. STP crews resumed excavation at 7 p.m. Tuesday. 
     
    Approximately two hours later, a sinkhole developed within STP’s work zone near South Main Street, about 35 feet north of the access pit. It is located more than 100 feet south of the cutterhead's current location, in ground that crews mined through last week. STP filled the sinkhole overnight with 250 cubic yards of concrete.
     
    This section of the tunnel drive is protected by an underground wall built by STP before tunneling. The wall was designed to isolate ground movement and protect the nearby Alaskan Way Viaduct. A manual survey of the viaduct conducted after the sinkhole developed found no movement. WSDOT and STP will continue surveying and monitoring the ground, viaduct, utilities and other structures.
     
    The cause of the sinkhole is still under investigation. STP is analyzing the portion of the tunnel that crews have excavated since mining resumed. There is no indication that any other locations have experienced ground loss. 
     
    STP is reviewing their daily operations as a result of this incident. Immediately they will enhance monitoring protocols by requiring crews to manually verify the amount of soil removed during excavation of each ring. 
     
    The protocols STP outlined to enhance monitoring were used in the first 1,000 feet of tunneling and WSDOT is disappointed they were not used when STP restarted tunneling in December 2015. STP has several hundred feet of mining before they reach the next planned maintenance stop. Before leaving the maintenance stop, STP’s operational protocols will undergo an additional review by an expert to assure public safety.
     
    STP has temporarily stopped mining to prepare the muck storage pit to receive excavated material. They plan to resume tunneling this week using trucks to remove excavated material. 
     
    Barging update
     
    STP’s inspection of piles at Terminal 46 is ongoing. The terminal is structurally sound, but crews noted damage to some piles. STP is preparing to install fenders along the pier that will allow them to continue safely barging from this location. 
     
    Work to move material from the damaged barge to a second barge is expected to be completed later today or tomorrow, according to STP. Once complete, STP will be able to determine the amount of clean material that spilled into Elliott Bay. Repairs will be needed before the damaged barge can be used again in the tunneling operation.
     
    Continued focus on safety
    Safety remains our top priority as we work to replace the seismically vulnerable Alaskan Way Viaduct. We expect STP to further investigate this incident and take the appropriate corrective action as they continue to build this important project.   
     

     

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  • Jan. 12 project update: Seattle Tunnel Partners working to resolve barging issue

    Jan. 12, 2016, 4:50 p.m. UPDATE: STP divers and marine surveyors continue to inspect damage at Terminal 46. Crews are assessing what needs to be done to safely stage a barge at Terminal 46 for loading.
     
    STP is using a barge-mounted clamshell to transfer material from the damaged barge to another barge.
     
    STP anticipates resuming tunneling and disposal of excavated materials after a third barge returns to the site from unloading excavated material at CalPortland’s Mats Mats reclamation facility in Port Ludlow. They must also confirm that a barge can be safely staged at Terminal 46.
     
    As of Tuesday morning, STP had mined more than 190 feet and installed 30 concrete tunnel rings since Bertha first moved forward in the pit on Dec. 22. This brings the total distance tunneled to 1,280 feet and a total of 188 concrete rings.
     
    Original post:
     
    One of the barges Seattle Tunnel Partners is using to haul away excavated material began to list or lean to one side as STP crews loaded it early Tuesday.
     
    To prevent damage to the conveyor system, STP released the barge from its moorage at Terminal 46. Some excavated clean soils were spilled into Elliott Bay. The barge then drifted into nearby Pier 48, which is owned by WSDOT and slated for demolition. 
     
    The barge has since been moved to the west end of Terminal 46. STP crews are working to transfer the material on the barge to another barge. STP is inspecting Terminal 46 and Pier 48 to determine if any damage occurred.
     
    Tunnel excavation is temporarily on hold as STP addresses this issue. We’ll provide additional updates as we receive new information.
     
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  • Jan. 7 project update: Bertha exits the access pit

    Bertha, the SR 99 tunneling machine, is now tunneling in Seattle soil after breaking through the access pit wall late Wednesday. Seattle Tunnel Partners has mined 73 feet and installed 12 concrete tunnel rings since Bertha first moved forward in the pit on Dec. 22. More mining is scheduled to occur this week. 
     
    Now approaching South Main Street, near Pier 48, Bertha is digging well below the area’s notorious fill soil. The top of the machine is approximately 80 feet below the surface in a mixture of glacially compacted material. Our Follow Bertha page has additional information about the conditions that Bertha will face over the remainder of the tunnel drive. Below is video of tunneling crews at work this week.
     
     
    STP’s mining schedule
    Currently, STP has two tunneling crews consisting of approximately 25 members each. Each crew is working six, 12-hour shifts per week. Mining progress during each shift may vary significantly from day to day. Some days crews may mine a long distance, while other days might be devoted exclusively to planned maintenance. 
     
    According to STP’s most recent schedule (pdf 258 kb), Bertha is expected to reach a planned underground maintenance stop just south of Yesler Way in late January. Once there, crews will spend approximately three weeks performing final maintenance before the machine tunnels beneath the Alaskan Way Viaduct. 
     
    WSDOT will fully close SR 99 through downtown for approximately two weeks while the machine passes beneath the viaduct. STP’s latest projections show that the closure will occur in March, but the actual closure date will depend on Bertha’s progress and the state cannot verify the contractor's schedule. Check our #99closure page as the closure approaches for additional details.
     
    One last thing of note: Crews have begun disassembling the massive red crane that was used to lift Bertha’s front end out of the access pit. We'll post photos of this work in the coming days.
     
    Look for another progress update next week.
     
    Recent updates 
     
    For earlier program updates, please visit our archive page.
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  • Jan. 4 project update: Bertha bores toward the access pit wall

    Seattle Tunnel Partners pushed the SR 99 tunneling machine forward in the access pit Monday, digging the 6.5 feet needed to build the tunnel’s 161st concrete ring. As of Monday afternoon, the machine’s cutterhead was positioned near the northern wall of the 120-foot-deep pit. 
     
    STP is preparing to mine through the approximately 15-foot-thick concrete wall in the coming days. Once beyond the wall, crews will begin tunneling through native soils that will serve as the next stage of STP’s testing process. This section of the tunnel route includes an underground wall that was built to protect the Alaskan Way Viaduct while crews continue to test the machine.
     
    Look for another progress update after crews have tunneled through the pit wall.
     
    Soil-removal barge arrives at Terminal 46
    With excavation underway again, STP is resuming its operation for removing excavated material from the tunnel. This is done via a conveyor belt that extends from the tunnel to the edge of the Port of Seattle’s Terminal 46. Material that contains concrete from the access pit wall will be hauled away by truck. Clean material – which crews will encounter once outside the access pit – will be taken by barge across Puget Sound to a reclamation site near Port Ludlow. There, the soil will be used to fill an old quarry.
     

     

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