FAQs

FAQs  

Have additional questions?

Email viaduct@wsdot.wa.gov or call 1-888-AWV-LINE (298-5463)

General program questions

  • + Why is replacing the viaduct important to public safety?

    The Alaskan Way Viaduct was built in the 1950s, and decades of daily wear and tear have taken their toll on the concrete structure. While it remains safe for everyday use, it also remains vulnerable to earthquakes.
     
    The 2001 Nisqually quake damaged the structure and hastened plans for its replacement. WSDOT has since repaired and strengthened the viaduct, and conducts twice-yearly inspections for safety. Parts of the viaduct, however, remain built atop fill soil that could liquefy in an earthquake. A tunnel will provide a much safer roadway for people travelling along SR 99. 
     
    Replacing the aging seawall is another element of improving the Seattle waterfront's resiliency against earthquakes. Visit the Waterfront Seattle website for information on the seawall replacement project.

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  • + Is viaduct replacement construction being coordinated with other nearby projects?

    WSDOT coordinates with partner agencies on nearly every aspect of the program including overall strategy and management, project schedules, construction and public involvement. Project coordination extends beyond the SR 99 viaduct replacement - coordination with the Seawall Project, the Seattle Multimodal Terminal at Colman Dock ProjectWaterfront Seattle and many other projects is vital to keeping traffic and construction moving.

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  • + What will happen to the Battery Street Tunnel?

    The Battery Street Tunnel was constructed in the 1950s and is at the end of its useful life. WSDOT’s final environmental document for the program included decommissioning (filling and sealing) the tunnel, and so WSDOT has a legal obligation to implement that plan.
     
    Community ideas have been proposed for alternative uses for the tunnel. However, given the age and condition of the structure, it would need significant and costly structural and system upgrades in order to be safe for other uses. WSDOT will be decommissioning the tunnel as part of a design-build contract that also includes demolishing the viaduct and connecting surface streets at the tunnel’s north portal.

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SR 99 tunnel questions

  • + When will the SR 99 tunnel open to drivers?

    The tunnel is scheduled to open to drivers in early 2019. Before then, the tunnel's safety systems must be tested and commissioned, and SR 99 must be realigned from running on the Alaskan Way Viaduct to running through the tunnel. The highway will be closed for approximately three weeks in order to finish this realignment by completing the tunnel's eight on- and off-ramps.

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  • + How will northwest Seattle residents get to SR 99?

    Residents from northwest Seattle will have two options to get to or through downtown Seattle. They could travel along Elliott Avenue, as they do today, and drive down a new bridge over the railroad tracks near Pike Place Market to a new Alaskan Way street along the waterfront. Alaskan Way will connect directly to SR 99 near South Royal Brougham Way.

    If northwest Seattle residents want to use the SR 99 tunnel, they could take the new two-way Mercer Street to Sixth Avenue North and enter the tunnel at Republican Street. They could also use any of the existing connections to Aurora Avenue north of Mercer Street. Our Future Access Page shows example routes.

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  • + How many lanes will the tunnel have?

    Each direction of the tunnel will have two 11-foot travel lanes with an eight-foot safety shoulder and a two-foot shoulder. These lanes will ensure enough space for all vehicles and legal size trucks.

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  • + Will the tunnel have mid-town exits?

    The SR 99 tunnel will not have mid-town exits. The tunnel and a new Alaskan Way street are designed to work together to replace the functionality of the viaduct. The tunnel will have the capacity to accommodate trips through downtown, while the rest of today’s viaduct users will access downtown using ramps at either end of the tunnel. Along the waterfront, a new Alaskan Way street will provide several east-west connections to downtown, replacing the function of today’s midtown viaduct on-ramp and off-ramp.

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  • + How much does the SR 99 Tunnel Project cost?

    The SR 99 Tunnel Project is estimated to cost $2 billion. The $2 billion cost includes Seattle Tunnel Partners contract with WSDOT for $1.5 billion as well as other projects that will connect the SR 99 tunnel with a mile-long stretch of new highway near Seattle’s stadiums at the south end of the tunnel and Aurora Avenue North at the north end of the tunnel. Additionally, new ramps and connections to city streets will be built.

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  • + Will the SR 99 tunnel be tolled?

    The 2012 Legislature directed WSDOT to collect tolls in the SR 99 tunnel in order to fund ongoing tunnel maintenance and raise $200 million to repay construction bonds used to build the tunnel. Tolls could also pay for future tunnel operations and maintenance costs, similar to other toll facilities in Washington. Tolling of the SR 99 tunnel is anticipated to begin after the tunnel opens to drivers

    The Washington State Transportation Commission is responsible for setting toll rates and is in the process of analyzing potential toll rates. They will oversee the toll rate-setting process in 2018.

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  • + Who will pay for the cost associated with the tunneling machine stoppage?

    In December 2013, Seattle Tunnel Partners (STP) stopped tunneling approximately 1,000 feet into the tunnel drive after measuring increased temperatures in the tunneling machine. While investigating the cause of the high temperatures, STP discovered damage to the machine’s seal system and contamination within the main bearing. STP and manufacturer Hitachi Zosen completed repairs to the machine in December 2015.

    In 2014, Seattle Tunnel Partners requested $125 million in additional compensation related to this stoppage. WSDOT denied that request after determining it had no contractual merit. The process for resolving disputes within the tunnel contract is prescriptive. It requires multiple steps by both parties. Should Seattle Tunnel Partners continue to pursue entitlement related to the stoppage, it will take time to resolve. Ultimately, the responsibility for costs associated with the delay will be determined through the project's design-build contract. 

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  • + Was any part of the tunneling machine saved for posterity or public viewing?

    The tunneling machine was owned by the original manufacturer, Hitachi Zosen, and the decision on what to do with the machine was theirs to make. Hitachi Zosen worked with The Port of Seattle and the Museum of History and Industry to preserve several pieces of the machine. The Port of Seattle received pieces of the cutterhead, and MOHAI received cutting tools and the machine's control panel. Most of the machine was recycled or preserved for use in other machines.

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Viaduct and demolition questions

  • + When will the viaduct be demolished?

    Crews will begin removing the Alaskan Way Viaduct after the new SR 99 tunnel opens to drivers. Tunnel opening is currently scheduled for early 2019. Removing the Alaskan Way Viaduct, which stretches along the waterfront from South King Street to Battery Street, is expected to take about six monthsIn 2011, crews demolished the southern mile of the viaduct, which accounted for nearly half the structure's total length. 

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  • + Is most of the traffic using the viaduct going to downtown or through downtown?

    WSDOT estimates there are more than 90,000 vehicles currently using the viaduct daily. Because this is an old road, there are no automatic traffic counts to pinpoint the number of vehicles that use the downtown ramps. A traffic count of three days in March 2018 (Tuesday – Thursday) showed that approximately 25,000 cars exited northbound at Seneca and Western Streets and approximately 31,000 cars entered the viaduct at Western Ave., Elliott Ave. and Columbia Street.

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  • + Is the viaduct still a safe structure on which to drive?

    Routine safety inspections and maintenance keep the viaduct safe for public use. In 2008, crews strengthened four column footings where the viaduct had settled approximately five-and-a-half inches into the ground since the 2001 Nisqually earthquake. The column safety project limits settlement in this area of the viaduct and prevents further damage to the structure.

    We also installed a system designed to close the viaduct automatically in the event of a moderate to severe earthquake in the greater Seattle area. The automated closure system consists of traffic gates at all viaduct access points controlled by an earthquake detection system. If the earthquake monitoring system detects significant ground movement, it will simultaneously lower all nine traffic gates and safely close the viaduct in two minutes.

    In 2011, crews demolished nearly half of the vulnerable viaduct near Seattle’s port and stadiums. Drivers now use a construction bypass connected to new side-by-side bridges built to current safety standards.

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Alaskan Way Viaduct looking north from SODO district.

Alaskan Way Viaduct looking north from SODO district. The southern mile of the viaduct was demolished in 2011.

 

Alaskan Way Viaduct looking south from Victor Steinbrueck Park, Pike Place Market.

Alaskan Way Viaduct looking south from Victor Steinbrueck Park, Pike Place Market.