• Lane closures on SR 99/Aurora Avenue North wrapping up early, next phase begins 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 has progressed ahead of schedule and the first phase of work is wrapping up one week early. By Friday afternoon, Feb. 5, the median lanes in both directions will be reopened and the southbound bus-only lane will be restored.

    Beginning Monday night, Feb. 8, crews will continue 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 will be 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.


    For questions or concerns about SR 99 lane closures, contact us at 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. 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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Program Spotlight

  • Good news for SR 99 commuters: first phase of lane closures wrapping up early

    Last week we reported that crews were making good progress as they worked to install sign foundations on SR 99/Aurora Avenue North in Seattle. Turns out good progress leads to good news: the first phase of sign foundation work is finishing ahead of schedule. By Friday afternoon, median lane closures should be removed and the southbound bus-only lane will be restored to normal operations.

    It may be tough to tell, but the new foundations for each sign on SR 99 extend 14 to 18 feet … more