SEATTLE — The Washington State Department of Transportation (WSDOT) closed two lanes of the First Avenue Bridge in Seattle late Wednesday night following an inspection, causing significant traffic delays into Thursday morning.
According to WSDOT, the affected northbound lanes on the First Avenue South bridge over the Duwamish River will be closed until further notice.
On Thursday afternoon, WSDOT sent out a release clarifying the reason for the closure. A bridge inspection on Wednesday evening had reportedly identified concerns with the steel grid deck.
In addition to the lane closures, “out of an abundance of caution,” WSDOT reduced the speed on the bridge to 25 mph to limit additional stress on the deck.
Bridge engineers were on site Thursday, “conducting a more detailed assessment,” but WSDOT says it’s too early to outline a repair plan or timeline, saying we should expect an update by Friday, March 6.
The closure of the right two lanes led to mid-morning backups on Thursday that stretched at least 3.5 miles on northbound State Route 509 heading into Georgetown and SODO. While the agency announced the closure on X, formerly Twitter, many commuters were unaware of the change until they reached the bridge ramps and slowed traffic.
Commuters traveling into the city faced unexpected delays throughout the morning rush hour. Jimmy Z, a local commuter, noted the difficulty the closure would cause for those using the route over the coming week.
“It’s kind of going to be tough coming through traffic for a couple of days,” Z said.
Other drivers reported their travel times more than doubled due to the congestion on the bridge and surrounding ramps. Catalina Orozco, a commuter traveling from Burien, said her trip took 30 minutes on a route that normally takes 10 to 15 minutes.
“I was going to detour, but I was like, ‘Ah, I’m already stuck in traffic. Might as well just ride it out,’” said Orozco.
WSDOT says the bridge remains open and operational, including for maritime traffic, and vessel openings will continue as needed. The HOV lane will also be open to all traffic until further notice to help with traffic flow, and traffic can exit at Michigan Street.
WSDOT also shared some background on the bridge:
“The First Avenue South Bridge is a movable double-leaf bascule bridge with two sections that lift from the center to allow marine traffic to pass along the Duwamish River. The northbound span was originally built in 1956 and rebuilt in 1998 and carries approximately 48,000 vehicles per day.
During its last inspection in 2024, the bridge was rated in fair condition. Like many structures across the system, this bridge requires ongoing maintenance and targeted maintenance repairs. In 2020, WSDOT undertook a select panel replacement project to replace 14 select deck panels. This lane reduction highlights the critical need for investment in preservation of our transportation system. Governor Ferguson proposed a $2.1 billion investment in preservation including $1.1 billion for bridges."
The lane closures come alongside existing lane reductions on northbound I-5 as part of the Revive I-5 program to preserve the Ship Canal Bridge. Together, WSDOT says these conditions will place additional pressure on the regional transportation system, and commuters should plan for ongoing delays, especially during peak travel times.
Travelers are encouraged to plan ahead, allow for extra time, consider alternate routes, and use WSDOT’s mobile app and real-time travel map for current road conditions.
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