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Out of an abundance of caution, we will close West Seattle High-Rise Bridge tonight to all traffic due to accelerated concrete cracking that was identified during a regular bridge inspection.

The bridge closure will begin at 7 PM tonight and will remain closed until further notice.

All vehicles will be prohibited from crossing the high-rise span of the bridge between I-5 and Fauntleroy Way SW.

Buses, freight and emergency vehicles will be moved to Spokane Street Bridge, which is also called the “low bridge.” Motorists should use the First Ave or South Park bridges.

We are putting signs in place to guide people through the new route. Prohibiting people and vehicles from the structure reduces the load weight and is necessary for public safety.

“Even in the midst of a pandemic, the Seattle Department of Transportation has been closely monitoring our critical infrastructure. Last night, our engineers identified safety risks in our West Seattle high rise bridge and are now taking swift action to protect the public by removing traffic from the bridge while next steps are assessed,” said Mayor Jenny Durkan. “Transit, freight and first responders will continue to have access to the Spokane Street bridge to ensure access to and from West Seattle. To the residents and businesses of West Seattle: I want to thank everyone for their flexibility and patience during this challenging time in Seattle’s history. It is a top priority to ensure safety and access to goods and transit, and we will be working as quickly as we can resolve this.”

A comprehensive assessment has already begun with a team of experts to determine the extent of the cracking and put together a plan for a near-term repair.

While the problems have accelerated at a rapid and unanticipated rate, this challenge did not appear out of the blue.

The West Settle Bridge was originally designed for three lanes of travel in each direction. As Seattle grew, the bridge grew to three westbound lanes and four eastbound. This added traffic, combined with the significant increase in size and weight of commercial vehicles (including buses), has only compounded the long-term maintenance challenges posed by the West Seattle Bridge. Further, 80 percent of the bridge load is dead load, meaning deterioration is possible even when all traffic is removed.

In 2019, however, the Federal load rating for this type of bridge changed and 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, 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 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

“We’ve kept a watchful eye on the West Seattle Bridge for years. Recently, a series of closely monitored cracks have grown faster than our team of experts had anticipated. Our engineers saw this acceleration as a clear warning sign that closer inspection is necessary, and complete closure is required to maintain safety as our top priority. As we close the bridge today, we will scale and accelerate a process already underway to determine next steps. Above all else, as the Mayor has made clear, we will make sure our first responders have quick and safe access to and from West Seattle,” SDOT Director Sam Zimbabwe said.

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.

King County Metro bus routes that typically travel the West Seattle 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 Spokane Street lower bridge and surface streets in SODO, and identify whether any bus stops might not be served as a result of the reroutes.

Once the bridge closes, we will continue its structural assessment and work on a near-term action plan to further stabilize the bridge.

The outcome of the near-term action plan will give us a better understanding of reinforcement work and a longer-term timeline.

The closure will remain until the bridge can be stabilized for use. SDOT is 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.