West Seattle Bridge will be repaired; Traffic back in Mid 2022 says Mayor Durkan
After 239 days of coping with the broken West Seattle Bridge, Mayor Jenny Durkan announced on Thursday morning that it will be repaired and return to service by mid 2022. A replacement is still potentially possible but given the forecast life of 15 to 40 years for the repaired structure it's uncertain when or what that might be. The repair will cost $47 million and be designed by consultant WSP.
The Mayor's office said that with federal stimulus funding options unlikely until later in 2021, the city would not have been able to secure needed funds in time to support a rapid replacement schedule. This timing was a key driver in the decision to pursue repair now.
The Mayor and Seattle Department of Transportation (SDOT) officials emphasized they have lost no time in the process of repair since the work done thus far to stabilize the bridge contributes to the eventually more complete repair.
The repair work yet to be completed will essentially be more of the same. Post Tensioning steel strands, affixed to anchors within the hollow concrete girders, each capable of carrying 280,000 pounds have been added primarily in the area where quickly advancing cracks forced the closure on March 23. The new work will add more strands along the full length of the bridge.
The Mayor and SDOT both were initially intrigued by what they called a "rapid replacement" concept advanced by engineering firm HNTB that would have restored traffic roughly a year later. But given the urgency of the need for restoration, not to mention the up to $522 million dollar cost, and potential permitting delays the Mayor chose repair as the best move for all stakeholders.
The Mayor and SDOT looked at other local projects regarding their permitting timelines and realized that even among the shortest of them, the Elliott Bay Seawall project required a U.S. Army Corps of Engineers permit at 14 months and a Shoreline Substantial Development Permit that took 9 months to get.
A replacement will still be necessary at some point according to SDOT and the Mayor agrees emphasizing that a type, size and location study will be started soon to in support of redundant modes of travel in and out of West Seattle, including bike and transit.
In addition to the post-tensioning strands, more monitoring gear will be installed on the bridge to enable SDOT to keep a watchful eye on conditions under load and in different weather events.
The schedule for repairs was laid out.
• Phase 1 (work nearly complete)
• Emergency closure of the bridge – Spring 2020
• Design, permitting and construction for first phase of stabilization work – April – December 2020
>> Phase 2 (next phase of repair work)
• Design, permitting and construction planning: Fall 2020 – Summer 2021
• Construction underway: Fall 2021 – Early 2022
• Open to traffic: Mid-2022
SDOT explained that the work would be completed using a General Contract/Construction Manager process.
• Key benefits of GC/CM include:
• Ability to engage contractor in design and construction planning phase
• Ability to identify schedule and cost savings
• Ability to develop sequencing plans that reflect complex environment
• Contract will include requirements for M/WDBE utilization, a commitment to hire a percentage of workforce from economically distressed zip codes, and support of apprenticeship training hours
SDOT said that a more refined cost estimate would be ready in early 2021, as designs advance
The up-front capital construction cost was identified with 0% of the design to be $47 million for the purposes of Cost Benefit Analysis
Other costs will include $50M for traffic mitigation and $10M for low bridge repair plus there will be ongoing maintenance and operations costs meaning the full cost of the repair, mitigation, maintenance and operation will be in excess of $110 million
The Mayor and SDOT said that local, state and federal partnerships may be pursued and that significant funding will be required in the future when the time comes to replace the bridge. The city will also complete a traffic and revenue study to understand and support developing a long term financing strategy for eventual replacement.
In the meantime SDOT is still in charge of managing low bridge access
The low or swing bridge opened in 1991 and was designed to carry 20,000 cars a day. Since the closure it has exceeded that number and restrictions were put in place between 5 a.m. and 9 p.m. to reduce the number of cars on the bridge at any one time.
Priority access for emergency vehicles and other users (workers at nearby port installations for example) was established.
SDOT noted that anyone can still cross the bridge between 9 p.m. and 5 a.m.
Coming up this month Automated enforcement cameras will be installed with testing starting in December and $75 tickets being issued starting in early January to violators.
SDOT recruited and convened a Low Bridge stakeholder committee to review and provide recommendations about future policy changes related to low bridge access. Managing access will be dynamic with on-going monitoring and adjustment
The work on Low Bridge strengthening activities will begin in 2021.
Congratulations to the West Seattle Bridge Now group. Thank you for your steadfast support of the citizens of West Seattle!