West Seattle High-Rise Bridge Safety Project

Updated May 18, 2020

What's Happening Now

We have been working tirelessly since closing the West Seattle High-Rise Bridge on March 23, to determine next steps and share that information with everyone who uses and depends on the bridge.

Currently we do not know if repair of the bridge is feasible technically or financially. If repair is feasible, it's likely this would only restore up to an additional decade of life to the bridge. In either case, we will need to replace the West Seattle High Rise-Bridge much sooner than promised when it opened in 1984. If repair is possible, under a "best case" scenario we do not anticipate the bridge reopening in 2020 or 2021. Despite these challenges, we are exploring all options to preserve the integrity of the bridge so that we can make the best decision possible for the residents of West Seattle and all who rely on this critical infrastructure.

Right now:

  • We're working to stabilize the bridge and prevent further cracking by fixing bearings on Pier 18 and constructing shoring support structures
  • We're exploring long-term solutions to see if it's feasible to repair the bridge
  • We're enlisting help from experts across the country and forming a Technical Advisory Panel
  • We're working with local transit agencies to keep people moving to and from West Seattle
  • And above all, we will remain nimble and flexible as we adapt to new information and needs

Read about our interagency task force and emergency response plan, Bridge Inspection Recommendations and other reports. You can also read our FAQs for more information.

Check out the following blog posts for more information:

Background

Though the problems have accelerated at a rapid and unanticipated rate, this challenge did not appear out of the blue. The West Settle High-Rise Bridge was originally designed for 3 lanes of travel in each direction. As Seattle grew, the bridge grew to 3 westbound lanes and 4 eastbound lanes. This added traffic, combined with the increase in size and weight of commercial and transit vehicles, has only compounded the long-term maintenance challenges posed by the bridge. Further, 80 percent of the bridge load is dead load, meaning deterioration is possible even when all traffic is removed.

Figure showing the progress of cracks located in the interior of West Seattle Bridge on the outer wall and underside of road deck.
Color-coded lines show recent crack growth since August 2019.

In recent years, the load rating for this type of bridge changed and so we assembled a team of engineers and experts from the public and private sectors to begin actively assessing the extent and growth of bridge cracking, and to create safety recommendations and a short-term repair plan. As a component of that review, we have been regularly inspecting concrete cracks in the West Seattle High-Rise Bridge. During the latest inspection, one of our engineers found known cracks in the concrete had worsened at a rate we and the outside specialists found unacceptable.

TimeBridge ConditionImpact on PublicResponse
2013 SDOT observes cracking in West Seattle Bridge None
  • Increase inspection frequency (annually)
2014 – 2019 Annual inspections confirm low level of crack growth None
  • Ongoing maintenance and monitoring
Aug 2019 Routine inspection reveals moderate crack growth None
  • Fill cracks with epoxy
  • Increase inspection frequency (monthly)
Oct, Nov, Dec 2019 Inspection reveals ongoing crack growth None
  • Begin analyzing mitigation options
Late Feb 2020 Engineering consultant recommends reducing traffic load Lane Reduction Under Consideration
  • Begin discussing mitigations and outreach approach, as well as potential repair approaches
March 19 2020 Engineering consultant notifies SDOT of new analysis raising larger concerns Potential for Full Closure
  • SDOT visits bridge on a daily basis
March 23 2020 Engineers discover new cracks, confirming growth has increased exponentially Immediate Full Closure
  • 9 am: Engineers assess crack growth and alert leadership
  • 11 am: Mayor Durkan approves plan to close bridge
  • 7 pm: SDOT begins implementing bridge closure

Table showing the timeline of inspections, bridge condition observations, resulting impact on the public, and our response.

West Seattle High-Rise Bridge Alternate Routes Map

Signs are in place to guide people through the new routes over alternative crossings of the Duwamish Waterway.

Alternative routes

Action Plan

We are continuing the structural assessment and working on a near-term action plan to further stabilize the bridge now that it has closed. The outcome of the plan will give us a better understanding of reinforcement work and a longer-term timeline. The closure will remain in place until the bridge can be stabilized for use. We are exploring ways to fund the design and construction of repairs to the cracked sections of the bridge. In the long-term, the bridge will be studied to determine its remaining useful life after operational repairs are made.

Collaboration with first responders and transit agencies

We are working with King County Metro and regional transportation, life-safety, and maritime partners to jointly develop a comprehensive traffic control plan to keep people and goods moving. This plan will include bus reroutes, general traffic detours to alternative streets and bridges, and a street-by-street approach to increase the capacity of detour routes to better carry the traffic using the high-rise bridge today.

The Seattle Police Department, Seattle Fire Department, and medical first responders are aware of the closure and planning detours. Our traffic control plan will use streets that accommodate the emergency response network to connect communities to hospitals as they are today.

King County Metro bus routes that typically travel the West Seattle High-Rise Bridge include RapidRide C Line, 21 and 21X, 37, 50, 55, 56, 57, 116X, 118X, 119X, 120, and 125. Routes 37 and 125 are not operating during Metro's temporary reduced schedule, which started March 23. Metro is working to finalize bus reroutes using the Low Bridge and surface streets in SODO, and identify whether any bus stops might not be served as a result of the reroutes.

Interagency Task Force and Emergency Response Plan

We've established an interagency task force to coordinate a unified emergency response if conditions of the high bridge reach critical thresholds. Read more about the emergency response plan on our blog.

The task force includes the City of Seattle, King County, Washington State, Port of Seattle, Northwest Seaport Alliance, United States Coast Guard (USCG),  and the  US  Army  Corps of Engineers.  If  we must activate the  task force's unified  emergency response,  a  unified command will be led by  the  Seattle Fire Department  (SFD), the Seattle  Department of Transportation (SDOT), the  Seattle Police Department  (SPD),  and USCG. 

These and other  agencies will work together  to prioritize public safety  and  provide  clear communication.  SDOT will manage  traffic  operations  to assist  emergency response  and provide consistent  updates to  the public.  SFD  will manage evacuation  and, if  necessary,  rescue  of  people near the bridge.  SPD  will manage traffic control  and  assist with evacuation.  USCG  will manage maritime  coordination  and communication.  Seattle Public Utilities and Seattle City Light will manage utilities to reduce impact on customers.  We have planned responses for three scenarios. 

  • Immediate evacuation  to be used if the daily in-person inspections indicates enough of a change to warrant the immediate evacuation of a small number of properties  (details shared below), though  we could  have hours or days before  actual bridge failure. 
  • One to five  days notice to be used if the new remote monitoring instrumentation, which will be fully functioning  in  mid May, indicates enough of a change to warrant execution of evacuation plans within one to five days.  If failure is anticipated, but not immediate, SFD and SPD will clearly communicate,  via direct site visits and other platforms,  when evacuation must occur. 
  • Controlled demolition  to be used if the change in the condition of the high bridge indicates the need for execution of an evacuation plan followed by a  controlled demolition.  

Vacinity Impact Zone

If  changes in the bridge  indicate a need to  activate our emergency response  plan, the only area  that will be evacuated are a small number of parcels in the "Fall Zone",  outlined in the image above.  

The perimeters of the Fall Zone were determined by modeling potential cracking scenarios and, out of an abundance of caution,  adding an additional 75' buffer.  The area spans 225' north and south of the bridge, 225' west of Pier 15, and 225' east of Pier 18, and includes the Spokane Street Low Bridge, parts of Harbor Island, the Duwamish Waterway, and areas on and around West Marginal Way.   

While the Fall Zone is the only area  that must be evacuated,  those who live or work on Harbor Island  should be aware that  emergency  response activity  may limit travel to and from the Island.    

It is recommended that  people on Harbor Island who are non-essential leave the island using the eastern approaches  if  they receive  any  notification  that the West Seattle High-Rise Bridge is at risk.  Those staying should know that emergency response could potentially block vehicle access to the  island.  

SDOT and other interagency partners have already done outreach to the parcels  in the  Fall  Zone  and  we are  working closely with the Port of Seattle  to provide continuous updates.  

There are no residential homes in the Fall Zone  that  would  need to be evacuated. People in nearby  neighborhoods, including Pigeon Point, can remain home.  

Should we need to activate our  emergency  response plan,  Seattle police and fire departments will  close access to roads  near the Fall Zone. 

In this situation, everyone  should  avoid the surrounding area to prioritize emergency access.  Following the map above,  Seattle Police  will be onsite to stop and  direct traffic  away from the Fall Zone.    

We will use multiple  communication  methods to get evacuation  messages  out to people in the impacted area, and beyond.    

  • AlertSeattle text message, email, and voice message - sign up today!  AlertSeattle  is the official emergency notification system used by the City of Seattle to communicate with city residents during emergencies.  If an evacuation is necessary, the City  will use  AlertSeattle  to  notify  everyone  in our database to stay away from the area in order to prioritize emergency access.    
  • Wireless Emergency Alert  (WEA)  text  messages -  WEA  is  an  alert system that  sends text messages to all cell  phones within a particular area. This is the same service that sends Amber Alerts. WEA  will send text message alerts to all cell  phones in  the  impacted area at the time of alert.  
  • United  States  Coast Guard  (USCG)  alerts - The USCG will send an Urgent Marine Information Broadcast over VHF Channel 16 to warn mariners to avoid the Duwamish Waterway, and they will use the USCG Alert Warning System to warn commercial operators and terminals on Harbor Island and the Duwamish Waterway. 
  • Twitter, Facebook, SDOT Blog, and Website - In the case of a  West Seattle High-Rise Bridge  emergency, SDOT will provide regular updates on  Twitter,  Facebook, and  our website.   

Project Library/Reports

Other Resources

We're here to listen and answer your questions as best we can. You can contact us at 684-ROAD@seattle.gov and 206-684-ROAD and visit our blog for more information on why we closed the bridge, alternate routes, how we caught the deterioration, and a recap of our presentation to the City Council. We're developing a way to keep your community engaged on this most important of issues to West Seattle and our region. And although bringing community together is hard right now, we remain committed to listening and finding ways to engage you remotely with technology in an equitable way.

Frequently Asked Questions

Though this is a difficult moment for many, we're grateful to our team for having the systems in place necessary to make sure we could act quickly to preserve life and safety.

The discovery of rapidly expanding cracks on the morning of March 23 required us to make an immediate decision to close the bridge that day.

In late February 2020, our engineering consultant recommended that the rate of deterioration made it necessary to consider traffic restrictions at some point in the near future. As our staff reviewed and came to the same conclusion in early March, and prepared to share that news with key stakeholders and the public, our structural engineering consultant notified us that they had conducted a new analysis that raised larger concerns. As a result, we conducted our own observations over the next few days to ground-truth their findings and on Monday, March 23, we identified significant new cracking. This confirmed that cracking had rapidly accelerated to the point where there was no other option but to immediately close the bridge.

We want to be very clear that during our frequent inspections of the West Seattle Bridge over the past several years, there was no indication that the bridge was unsafe for ordinary use or that preventative maintenance plans would impact normal use of the bridge until very, very recently.  In the last few weeks, third party experts suggested that lane reductions or closure may be necessary for repairs at some point in the future. As we were preparing to share that news, accelerated cracking in the bridge over the course of a few days — caught by our close monitoring process — forced us to make the difficult decision to close the bridge, immediately. 

This outcome, without a robust opportunity for public engagement and mitigating surprise, is never one we want and it's our hope that recent efforts to engage West Seattle around existing projects make that clear. Please know that we are thinking of the people and businesses of West Seattle every day as we work tirelessly to reopen the bridge safely.

More thorough information about how we monitor the West Seattle Bridge check out our bridge reports.

We regularly inspect our bridges. The events of the past few days are a notable example of why those efforts are critical and why we take this responsibility so seriously. We did not make this decision lightly, but ultimately, we prioritize safety above all else.

During a 2013 routine inspection of the West Seattle Bridge, our bridge inspectors discovered four sets of cracks in the bridge support structure. We've inspected the bridge every year since then, which is twice as frequently as required by federal guidelines. Those annual inspections did not indicate a need for repairs that would significantly disrupt standard use of the bridge.

During a 2019 assessment of the bridge's ability to carry heavy loads, our structural engineering consultant mapped the cracks in the bridge and discovered that they had grown since the previous year's inspection. Along with our engineering consultant, we continued to closely monitor these cracks and carry out maintenance.

We want to be very clear that during our frequent inspections of the West Seattle Bridge over the past several years, there was no indication that the bridge was unsafe for ordinary use or that preventative maintenance plans would impact normal use of the bridge until very, very recently.

In late February 2020, our engineering consultant recommended that the rate of deterioration made it necessary to consider traffic restrictions at some point in the near future. As our staff reviewed and came to the same conclusion in early March, our structural engineering consultant notified us that they had conducted a new analysis that raised larger concerns. As a result, we conducted several observations over the next few days to ground-truth their findings and on Monday, March 23, we identified significant new cracking. This confirmed that cracking had rapidly accelerated to the point where there was no other option but to immediately close the bridge.

More thorough information about our monitoring of the West Seattle Bridge check out our reports.

Along with our partners, we have made the reopening and mitigation of the West Seattle Bridge closing a top priority with teams working tirelessly to safely restore access. At present, however, the bridge will remain closed until further notice. At this time, we cannot give a definitive date for when the High Bridge will reopen, but we anticipate a lengthy closure. In the immediate term, we will take all measures to preserve the integrity of the bridge so a long-term solution can be put in place. We are working tirelessly with our partners to assess what near-repairs need to be made now and in the future, how long they will take, and how to fund them. We will continue to share updates as we have them.

Currently, we have standard vehicle barriers in place as we plan for a more permanent barrier. We first need to better understand the length of closure to determine the best type of permanent barrier to use. To do this, we are currently assessing what near-term repairs need to be made, how long they will take, and how to fund them.

At this time, the Low Bridge remains closed to people driving general purpose vehicles to keep essential and life-safety services moving. Considering the current public health emergency, our top priority is emergency access to hospitals and protecting the supply chain, so we are reserving access to emergency vehicles, freight trucks, and transit buses, and working with our partners at the Seattle Police Department, the Seattle Fire Department, the Port of Seattle, and  King County Metro to determine the extent of the access limitations.

Currently, detour signs are posted and Seattle Police Department officers are stationed at either end of the Low Bridge to direct general purpose traffic away from the bridge. We are monitoring traffic on the Low Bridge and as new traffic patterns develop, we may be able to adjust access.

Attempting to shift all the traffic from the High Bridge to the Low Bridge would create traffic congestion and long traffic queues, even while there is reduced traffic due to the Governor's "Stay Home, Stay Safe" order. The High Bridge carried significantly more vehicles because it has seven lanes compared to the two lanes on the Low Bridge. We prioritize the movement of transit, freight, and emergency vehicles on city streets and used this prioritization to limit vehicle demand on the Low Bridge in a way that keeps people, goods, and essential services moving.

We understand the challenge the closure of the High Bridge presents to the community. We did not make this decision lightly, but ultimately we prioritize safety above all else.  

We are not issuing passes. Only people driving transit buses, freight vehicles, and emergency vehicles are allowed to use the Low Bridge. We are working with our partners at the Seattle Police Department, the Seattle Fire Department, the Port of Seattle, and King County Metro to determine the extent of the access limitations.   For regular project updates, please visist our project webpage or subscribe to project emails

In addition to signs and pavement markings, our partners at the Seattle Police Department are present to help educate people about the Low Bridge restrictions and enforce these rules. Officers will stop or redirect people driving personal vehicles, vanpools, private shuttles, and other vehicles that are not transit buses, freight vehicles, or emergency vehicles. 

For regular project updates, please check out project webpage or subscribe to project emails

We acknowledge it is critical for doctors, nurses, researchers and first responders to get to their jobs. At the same time, we must reserve access to the Low Bridge to emergency vehicles transporting critically ill patients. Many people who live and work in West Seattle serve many kinds of essential functions — we need to maintain equity for all of them. The Low Bridge is currently open to essential workers who get to work by taking transit, walking, and biking. It's also open to people using emergency vehicles and transporting freight as part of their jobs. For essential workers who are driving private vehicles, they are directed to the 1st Ave S Bridge.

We understand the inconvenience the closure of the High Bridge poses to the community. We did not make this decision lightly, but ultimately, we prioritize safety above all else.  

At this time, the Low Bridge remains closed to people driving general purpose vehicles. People driving emergency vehicles, freight vehicles, and transit buses are allowed to use the Low Bridge. A freight vehicle is defined as a vehicle with a gross vehicle weigh of 10,000 pounds and higher.  For regular project updates, please visit our project webpage or subscribe to project emails

At this time, the Low Bridge remains closed to people driving general purpose vehicles to keep essential and life-safety services moving. Considering the current public health emergency, our top priority is emergency access to hospitals and protecting the supply chain, so we are reserving access to emergency vehicles, freight, and transit, and working with our partners at the Seattle Police Department, the Seattle Fire Department, the Port of Seattle, and King County Metro to determine the extent of the access limitations.

The Low Bridge remains open to pedestrians, including people who use mobility devices, and bicyclists.

No. The Low Bridge is reserved for emergency vehicles, freight trucks, and transit buses to keep essential and life-safety services moving. We are monitoring traffic on the Low Bridge and as new traffic patterns develop, we may be able to adjust access.

The Coast Guard has sent a notice to non-commercial vessels with a request to request openings during non-peak commute times. SDOT is also making a formal request to restrict bridge openings during peak commute times, which could take several weeks or months to implement.

We are looking to provide several alternative routes. We need to be careful not to direct drivers to prefer any one route to encourage traffic to spread throughout the system to avoid congestion as much as possible.

We are working with King County Metro and regional transportation, life-safety, and maritime partners today to jointly develop a comprehensive traffic control plan to keep people and goods moving. This plan will include bus reroutes, general traffic detours to alternative streets and bridges, and a street-by-street approach to increase the capacity of detour routes to better carry the traffic using the high-rise bridge today.

The Seattle Police Department, Seattle Fire Department, and medical first responders are aware of the closure and planning detours. Our traffic control plan will use streets that accommodate the emergency response network to connect communities to hospitals as they are today.

We are monitoring traffic on the Low Bridge and as new traffic patterns develop, we may be able to adjust access.

The signals at this intersection were upgraded on April 1, to improve traffic flow and allow our staff to manage the signal in real-time. In order to get as many people through the intersection as we can, we also extended the length of the green light. We monitor this intersection regularly and will continue making adjustments to improve traffic flow. This is a complex intersection with five directions of traffic each waiting their turn to move through the intersection. At any given time, four groups of traffic are waiting for a green light and it can be a longer wait than the average signal.  

 For regular project updates, please visit project webpage or subscribe to project emails

We are continuing to work with the engineering consultant that recently assessed the cracking on the West Seattle Bridge. Future work requiring a bid will be posted on our procurement website.

To help manage traffic during the closure of the West Seattle High Bridge, we installed a temporary signal at Highland Park Way SW and SW Holden Street intersection. Safety improvements for the intersection had already been in progress, including a permanent 4-way traffic signal. We will continue moving forward with the permanent safety improvements and collect community input on the project while the temporary signal remains in place. For more information on the Highland Park Area Traffic Safety Improvements, please visit the project webpage.