The West Seattle Bridge will remain closed to traffic at least until 2022 because of the prolonged efforts needed to first brace, and then repair, the cracking concrete main span, the city now predicts.
And it’s not certain yet whether the bridge can even be saved.
“It may not be possible to repair the bridge as it currently is,” Sam Zimbabwe, director of the Seattle Department of Transportation (SDOT), warned in a news conference Wednesday. “That may be because of the deterioration of the bridge, or the technical or financial feasibility of repair.”
A two-year closure is sure to frustrate the 100,000 drivers and 25,000 transit riders each day who relied on the bridge, until the coronavirus outbreak dramatically cut traffic. Later this year when people presumably resume trips to jobs, schools and leisure activities, Seattle’s busiest city-owned bridge will not have recovered.
City leaders declared an emergency closure March 23, after diagonal cracks grew 2 feet in two weeks — following rapid growth since late 2018 — in the bridge’s hollow concrete girders below the bridge deck.
Residents and agencies alike will be forced to rethink how people travel. Thousands may opt to continue telecommuting.
Mayor Jenny Durkan mentioned more transit combined with park-and-ride lots, which the city typically forbids.
“I think the reality is, given how long this bridge is going to be out, we’re going to have to do more of everything and be more creative in how we do it,” Durkan said.
That could include new bus lines that go directly to Sound Transit stations, she said. No details or sites have been chosen yet, but a temporary park-and-ride lot did serve water-taxi users in January 2019 during a Highway 99 closure.
The bridge closure is “a big, big deal — and that’s capital Bs, capital Is, capital Gs,” said Deb Barker, a 35-year resident and head of the Morgan Community Association, a West Seattle neighborhood group. Residents have already begun to notice cut-through traffic, she said.
City Councilmember Lisa Herbold, who represents West Seattle and South Park, compared the next 21 months to last year’s “Seattle Squeeze,” when downtown commuters endured the Alaskan Way Viaduct shutdown, renovation of the state ferry dock and sluggish bus detours.
“This is going to be longer and it will affect more people,” Herbold said.
“It’s a given that with coronavirus, we’re already stressed enough, but this is definitely adding a lot of stress and uncertainty,” said Larry Wymer, an engineer and board member of the Admiral Neighborhood Association in West Seattle.
“We don’t know how many businesses may not survive the combination of the coronavirus and this,” Wymer said. He said he and his wife are even considering moving off the peninsula, if the long-term effect on their commutes is dire enough.
The best-case scenario, Zimbabwe said, is to complete repairs that keep the bridge in service for another 10 years. The crossing, which opened to traffic in 1984, will definitely not reach its full 75-year design life, he said.
Just to complete this year’s first step — to stabilize the 590-foot long span over the Duwamish Waterway, do major maintenance within the low-level swing bridge, and perform traffic control and community outreach — is estimated at $33 million the city hasn’t found yet.
SDOT said another problem must be fixed immediately. A bearing atop Pier 18, which supports the eastern side span at Harbor Island, is stuck in a way that resists normal thermal expansion, causing a shock that stresses the bridge, said Matt Donahue, SDOT roadway structures director.
Engineers won’t know for sure how, or whether, the bridge can be repaired until after the Pier 18 troubles are solved, Zimbabwe said. A technical panel is being assembled that will include experts in bridges, construction, soils engineering and the maritime industry.
The main span sits 140 feet over the shipping lane and SDOT will need federal permits.
Zimbabwe said it’s too early to know whether the bridge, once reopened, could take heavy trucks and buses as before, or whether it’s possible to re-introduce traffic lanes in phases during repairs. Seattle City Council members at a March 30 briefing hoped for some kind of near-term, interim repair that would allow at least some traffic to flow.
As for repairs or replacement, Durkan said she’s spoken to U.S. Democratic Sens. Patty Murray and Maria Cantwell in hopes the bridge will qualify for infrastructure stimulus money from the federal government.
Durkan said she has also talked with Sound Transit CEO Peter Rogoff about the idea of combining a new road bridge with a voter-approved light-rail bridge.
“We’re going to have discussions about whether to combine the bridges, and at what cost. What we don’t want to do is lose time,” she said.
The city noticed an unexpected spread of cracks in 2013, but rather than try costly repairs, chose to monitor them by attaching gauges, squirting epoxy into cracks and conducting more frequent, yearly inspections, instead of the standard two-year interval.
The crack growth increased during 2018 and 2019. By February, engineering consultants proposed a reduction in traffic lanes and weights as cracks grew.
The cracks could be due to a number of factors, including concrete shrinkage and the addition of a fourth eastbound lane often packed with cars, trucks and buses weighing about 50,000 pounds. Two consultants have speculated that the 2001 Nisqually earthquake — which shook the bridge 3 inches according to SDOT inspection records — could have weakened it years earlier.
SDOT has said it’s been paying special attention to the cracks for years, and only in recent months did the damage begin to raise questions about the bridge’s stability.
Zimbabwe, who moved to West Seattle from Washington, D.C, early last year, is the fifth SDOT director since cracks became conspicuous in 2013. Durkan said he’s dealt with nonstop problems including a snowstorm, Alaskan Way Viaduct shutdown, detours downtown and now the West Seattle Bridge.
“I have full confidence in you [Zimbabwe] and the Seattle Department of Transportation to make sure we are doing everything we can be doing to get through this,” Durkan said.
Metropolitan King County Councilmember Joe McDermott, who represents West Seattle, said Wednesday he was “utterly stunned at the news.”
“The city owes us all an explanation on how on earth it let this much deterioration to Seattle’s most used arterial slip by and reach this point,” McDermott said in a statement. Planning for a replacement is “an all hands on deck situation for leaders in Washington state,” McDermott said.
West Seattle residents have contemplated being cut off from the rest of the city before, but didn’t expect it to arrive like this.
“A lot of neighborhood groups and active folks here have been scared for years about what an earthquake would look like and its impact for the West Seattle peninsula if it damaged the bridge,” said Michael Taylor-Judd, chairman of the West Seattle Transportation Coalition. “That’s what we’re looking at.”