West Seattle High-Rise Bridge Safety Program

Updated November 19, 2020

What's Happening Now?

The fastest path: Building on months of stabilization work, major repairs slated for West Seattle High-Rise Bridge

On Thursday, Nov. 19, Mayor Jenny A. Durkan announced that she has instructed the Seattle Department of Transportation (SDOT) to restore travel across the Duwamish by repairing the West Seattle High-Rise Bridge. SDOT has nearly completed Phase I of this two-part repair process, as the stabilization work concludes in December. She also directed SDOT to continue early design work for an eventual replacement of the bridge.

Watch the Mayor's announcement on YouTube.

"After weighing a number of factors and hearing from many stakeholders and members of community, I have decided to move forward with repairing the High Rise Bridge. This corridor is simply too important to our economy and our residents to face potentially more than 3 years of uncertainty. Repair will simply get West Seattle reconnected the fastest.  Work has already begun on the repair plan and we anticipate we may be able to traffic by mid 2022."

Mayor Durkan

The Mayor's rapid decision to initiate stabilization repairs in March means we are already months down the repair pathway selected today, ensuring that not a moment of forward-progress has been lost. Today's announcement continues work that has been happening on, under, and inside the bridge six- to seven-days-a-week.

Learn more about the decision in our blog post

Project Overview

On March 23, 2020, we closed West Seattle High-Rise Bridge to all vehicle traffic. The rapid announcement to close the bridge stemmed from regular inspections that indicated accelerated growth of new and existing structural cracks. 

Since the closure of the West Seattle High-Rise Bridge, we've worked to simultaneously advance all efforts to efficiently pursue both a repair or replace scenario, while mitigating traffic and environmental impacts on the ground. By advancing all pathways at once, we have lost no time while we carefully and thoroughly assess which avenue - repair or replace - provides the safest, most certain outcome for the region over the long-term. 

Historically, the West Seattle High-Rise Bridge is the City's most used bridge, typically carrying an average of over 100,000 cars, trucks and buses every day. The closure has caused a significant disruption to traffic in the surrounding area of West Seattle, South Park, Georgetown, SODO, and Seattle as a whole. 

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

Background that led to High-Rise Bridge closure

The decision to close the High-Rise Bridge on March 23, 2020 came from close monitoring and regular inspections that indicated a sudden change in crack growth rate.

During a 2013 routine inspection of the bridge, our inspectors discovered four sets of cracks in the bridge support structure. Some cracking is normal for this type of bridge, but we decided to increase monitoring to keep an eye on it. Between 2013 and late 2019, we regularly monitored the cracks, preformed ongoing maintenance, and began analyzing mitigation options, none of which would have disrupted normal use of the bridge. During this time, we did not observe deterioration that called for remediation efforts that would disrupt normal, daily use of the West Seattle High-Rise Bridge by the public.

On March 19, 2020 our structural engineering consultant notified us that they had completed new analysis of previously collected data raising larger concerns and a recommendation that closure may be necessary at some point.

We conducted daily observations over the next four days to verify the consultant's recommendations in the field.

It was not until Monday, March 23, 2020 that we found significant new cracking, which confirmed growth had rapidly accelerated to the point where there was no other option but to close the bridge. 

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 between August 2019 and March 2020. Blue areas indicate rapid advancement of cracking over a three-week period in March 2020.

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 to promote safety for the traveling public.

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.

Map showing detour routes through West Seattle during the High-Rise Bridge closure

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 detour routes. Our traffic control plan uses 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, was installed 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 westseattlebridge@seattle.gov and (206) 400-7511 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, 2020 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 verify their findings and on Monday, March 23, 2020, 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. 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.

For 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.

Updated 10/26/20


With public safety as our top priority, Low Bridge access is restricted primarily to ensure efficient emergency vehicle access across and around the bridge.Who CAN use the Low Bridge

  • Emergency vehicles  
  • Transit vehicles (King County Metro buses and school buses)
  • Freight vehicles
  • People walking, rolling, using a scooter, or biking (Low Bridge path)
  • Employer shuttles
  • Vanpools
  • People with placards (currently 160 distributed)
  • People driving personal vehicles at night (from 9 PM to 5 AM daily)

Who CANNOT use the Low Bridge

  • Ubers, Lyfts, or other ride-sharing vehicles 
  • People driving personal vehicles, including motorcycles, during the day (from 5 AM to 9 PM daily)  

The placard system was based on data that showed we could allow 160 more vehicles to use the Low Bridge without impacting emergency response vehicles. The 160 is a small number that was distributed among:  

  • Maritime/industrial users proximate to Harbor Island
  • International Longshore and Warehouse Union   
  • West Seattle Chamber 

The placard system is temporary until automated enforcement of the Low Bridge begins by the end of 2020 when all use must be tied to individual license plate numbers.  

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.

Signs notifying people driving that the Low Bridge is closed except for buses and authorized vehicles, as well as detour signs, are posted at multiple points at either end of the Low Bridge.  

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.

Under the existing Low Bridge Access policy, a freight vehicle is defined as a vehicle with a gross vehicle weight of 10,000 pounds and higher. 

The types of authorized freight vehicles may change as we move to automated enforcement in early 2021. 

At this time, people driving freight trucks can access the Low Bridge. We are monitoring traffic on the Low Bridge and as new traffic patterns develop, we may be able to adjust access. We acknowledge it is critical for members of freight and maritime community to get to their jobs. At the same time, we must ensure efficient access across and around 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. With public safety as our top priority, Low Bridge access is restricted primarily to ensure efficient emergency vehicle access across and around the bridge. 

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

Motorcycles can use the Low Bridge (Spokane Street Bridge) from 9 PM to 5 AM. At all other hours, motorcycles are not currently allowed under the dynamic Low Bridge Access policy. 

While an individual motorcycle is smaller than a car, it still requires roughly the same amount of room on all sides to travel safely. This is because a large truck or bus needs just as much room to stop safely when they are following a motorcycle as they do for any other kind of vehicle. While motorcycles could travel side by side, most motorcycles travel on their own and occupy an entire lane.

From a traffic engineering perspective, motorcycles take up the same amount of room as a car. This is especially true in stop-and-go conditions where congestion is created by the cumulative reaction time of every individual driver waiting to move forward after the vehicle in front of them moves forward. The number of vehicles in a line of traffic is just as important as the size of each individual vehicle, and so motorcycles could be expected to add to congestion at any intersection, just like cars do.

Additionally, we have safety concerns about motorcycles travelling next to large trucks and buses in stop-and-go conditions, especially because congestion would likely increase considerably if more motorcycles used the Low Bridge. 

Updated 10/26/20

With public safety as our top priority, Low Bridge access is restricted primarily to ensure efficient emergency vehicle access across and around the bridge.

Who CAN use the Low Bridge

  • Emergency vehicles  
  • Transit vehicles (King County Metro buses and school buses)
  • Freight vehicles
  • People walking, rolling, using a scooter, or biking (Low Bridge path)
  • Employer shuttles
  • Vanpools
  • People with placards (currently 160 distributed)
  • People driving personal vehicles at night (from 9 PM to 5 AM daily)

Who CANNOT use the Low Bridge

  • Ubers, Lyfts, or other ride-sharing vehicles 
  • People driving personal vehicles, including motorcycles, during the day (from 5 AM to 9 PM daily)  

The placard system was based on data that showed we could allow 160 more vehicles to use the Low Bridge without impacting emergency response vehicles. The 160 is a small number that was distributed among:  

  • Maritime/industrial users proximate to Harbor Island
  • International Longshore and Warehouse Union   
  • West Seattle Chamber 

The placard system is temporary until automated enforcement of the Low Bridge begins by the end of 2020 when all use must be tied to individual license plate numbers.  

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.