Drivers who lose time in West Seattle Bridge detours will face more frustration in January, when the state closes two southbound lanes of its First Avenue South Bridge for urgent repairs.
The job will worsen traffic bottlenecks along the main alternative to the cracked West Seattle highrise, which was closed March 23 because of runaway shear cracks. Mayor Jenny Durkan is expected to announce after next week’s election whether the city will repair the high bridge or replace it.
At the First Avenue South Bridge, bearings are damaged above two piers of the southbound span, built in 1996.
The Washington State Department of Transportation (WSDOT) anticipates two of its four lanes will be closed over a four-week period, spokesperson Tom Pearce said. Four full southbound overnight closures also are planned. Exact dates are still being determined.
All lanes of the parallel northbound span will remain open.
The lane closures will worsen traffic for motorists detouring to reach West Seattle, as well as Burien-bound drivers caught in the congestion. Drivers heading to the peninsula are losing a typical 15 to 30 minutes — and sometimes longer — in each direction as they meander through Georgetown and over the First Avenue South Bridge.
The four-lane southbound crossing historically serves 47,000 vehicles a day. Despite the COVID-19 pandemic, combined two-way traffic has grown nearly 10% this year, from 96,370 to 105,890 weekday trips.
If that crossing is jammed, drivers can backtrack to a couple other Duwamish River bridges, just south of the city limits. Those are the South Park Bridge, where detouring cars already fill a neighborhood arterial, or the short bridge from Boeing Access Road to International Boulevard South in Tukwila, then uphill into White Center.
Deb Barker, Morgan Community Association president, expects some drivers will go all the way south on I-5 to Southcenter in Tukwila, turn uphill to Highway 518 in Burien and then backtrack into West Seattle, a route she already takes sometimes.
“It may be good for people to figure out some other routes, besides First,” she said.
Lora Radford, executive director of the West Seattle Junction Association, said that if possible, the state should avoid restricting other Duwamish River bridges while the West Seattle Bridge is closed.
However, the Seattle Department of Transportation (SDOT) doesn’t expect to finish lasting repairs to the cracked highrise until early 2022, or it may skip that step and move to demolition and a replacement, restoring capacity in 2023 at the soonest.
“If it’s unavoidable, if it’s a safety issue, we’ll adapt like we did through 2020,” said Radford, who serves on a task force advising the city about the West Seattle Bridge. “It will be yet another psychological strain.”
WSDOT says major repairs to the First Avenue South Bridge can’t wait much longer.
Damage has worsened where two piers support the horizontal bridge girders. Girders are welded to steel bearing plates, which in turn rest on a masonry plate atop concrete grout, Pearce said.
“We’ve been keeping an eye on it for years,” he said.
Crews performed stopgap repairs in early October to stick steel shims into crevices above the grout. That’s in addition to a $2 million electrical upgrade to drawspans in 2019-20 and some new steel-deck segments installed on the northbound drawspan.
During the January repairs, workers will jack up and then brace the girders by a few inches, while grout and contact plates are replaced, Pearce said. There’s no cost figure yet because the project is still being designed.
Two traffic lanes will be maintained by converting either the carpool lane or the right-side exit lane to general traffic use as work zones shift.
The lane closures will come shortly after automated camera enforcement begins on the city’s Spokane Street lower swing bridge, which is restricted to buses, freight, emergency vehicles, and permitted waterfront workers from 5 a.m. to 9 p.m. Violators will face a $75 fine, beginning in January, city staff say.
Traffic restrictions on the swing bridge will likely continue. SDOT seeks to “ensure that emergency services have a clear and dependable route to hospitals across the West Seattle Low Bridge,” spokesperson Ethan Bergerson said in a statement.
Durkan’s office said she’s instructed city staff to coordinate with the state to minimize delays to travelers.
“These are important safety repairs, so it is also a priority to ensure the [First Avenue] bridge is safe for traffic and can continue to be relied upon as we manage the continued impacts of the highrise bridge closure,” the mayor’s office said in a statement.
The city has been making signal and turn-lane improvements to help move traffic, and just opened the Lander Street Bridge over train tracks in Sodo.
Mark Jacobs, a private-sector traffic engineer who lives in West Seattle, suggests the state start the First Avenue South repairs immediately, before in-person school resumes and people isolating due to COVID-19 begin traveling more regularly.
“My sense is, if you’re going to do it, get it done now,” Jacobs said.
WSDOT’s Pearce said the agency needed time to solicit contractor bids and coordinate marine openings with the Coast Guard.
The Spokane Street swing bridge itself needs repairs to underwater supports, pivots and concrete girders over the next couple years.