The tenth meeting of the West Seattle Community Task Force brought the Cost Benefit Analysis process to a close and shared the conclusions and weighting the six potential options that were considered regarding the repair/replace decision. That decision is expected next week by Mayor Jenny Durkan. The full meeting (though there were technical issues with ZOOM) can be viewed online via YouTube here.

The thrust of the meeting looked as if the short term repair followed by a superstructure replacement is the most likely of paths going forward. No costs other than relative level of cost were included in the presentation.

Mayor Durkan stated her goals for the project:

• Protect lives and preserve public safety

• Deliver the safest, fastest solution that provides the greatest certainty and benefit to all communities in and around West Seattle and the city, region, and state

• Identify the pathway with the highest level of certainty because there’s no room for “hope and a prayer” or “benefit of the doubt” in 2020

•Minimize the impact of the closure on communities, particularly Black, Indigenous and People of Color communities

• Provide stability and confidence for significant economic investments being made by the Port of Seattle and Northwest Seaport Alliance, Sound Transit and others

• Secure needed funding from Federal and State partners

 

The meeting went to a Q&A session with the Mayor and members of the Task Force.

That was followed an update on the bridge provided by SDOT's Heather Marx. She explained that stabilization measures were still underway as post-tensioning brackets were being installed inside the bridge girders. That work is necessary just to make the bridge stable.

Next up was a report on the traffic mitigation efforts, radar speed signs and other work SDOT has been doing recently.

Marx and Greg Izzo of SDOT then led the discussion regarding the six options the Cost/Benefit Analysis the combined groups have been considering. Those groups include SDOT, the Community Task Force, the Technical Advisory Panel (TAP) and SDOT's consultants WSP.

The TAP is developing technical guidance for whatever is to come next and noted that all the alternatives are technically feasible from an engineering standpoint. 

TAP Key considerations include:

• Application of Weighted Attributes

• Geotechnical and Seismic Resiliency

• Risks and Uncertainties

• Pier and Superstructure Connections

Barbara Moffat of the Technical Advisory Panel was part of the presentation and noted that the costs were not the only important considerations.

The ALTERNATIVES

Note: No costs were included in the presentation

Izzo explained that in simple terms Repair (Alternative 2) vs Replace (alternatives 4,5 and 6), repair is clearly less expensive and faster but its seismic safety, and potential limited lifespan were considerations. The replace alternatives while more costly would also take longer to get traffic back on the bridge.

This story will be updated with more comments from the meeting attendees.