WSDOT announces 3-phase repair plan for 1st Avenue S. bridge, 3-day closure starts Monday
Mar 5, 2026, 4:32 PM
A photo of a road closed sign. (Photo courtesy of KIRO 7)
(Photo courtesy of KIRO 7)
On Feb. 18, crews working for the Washington State Department of Transportation (WSDOT) discovered cracks in some of the steel grates on the 1st Avenue S. bridge draw span during routine inspections.
The discovery was concerning enough that WSDOT immediately closed two lanes that were affected, stating that the department would assess the situation and give an update on the extent of repairs by early March.
On Tuesday, that update was announced, and it’s not what commuters were hoping for. The repairs will be completed in three phases over the next year, beginning with a full closure of northbound SR 99 at the bridge on Monday, March 9, 2026, according to WSDOT.
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Phase 1: Stabilizing the bridge (March 9-11)
During the full northbound closure from March 9 to 11, crews will modify existing grated panels and install steel plates over the cracked grates to restore safe vehicle access across all lanes. Welding and reinforcement work will strengthen the most affected sections of the bridge deck.
The temporary steel plating and reduced speed limit are intended to reduce stress on the deck and provide safe passage across the bridge until permanent grate replacements are installed.
The bridge will remain operational for marine traffic but will be closed to vehicles during these repairs.
Phase 2: Replacing nine failing panels before summer (Starting mid-to-late April)
The next phase involves full replacement of nine steel grate panels that inspectors deemed to be in the worst condition. Manufacturing these panels is underway and is expected to take approximately six weeks, with installation scheduled to begin as soon as they are delivered.
This work will also require a full northbound closure of the 1st Avenue S. bridge. This work is expected to start in mid-to-late April, pending panel delivery and U.S. Coast Guard coordination.
The goal is to complete the replacement of these nine panels before the 2026 FIFA World Cup begins in June, when hundreds of thousands of spectators will visit the greater Puget Sound region. Completing this work now ensures that SR 99 remains a viable route during a period when the transportation system will be in high demand.
Once this phase is complete, all northbound lanes will reopen at normal speeds.
Phase 3: Long-term preservation work in development (2027)
Design is underway for a full replacement of the northbound bridge deck, with construction expected in 2027. This project will address broader needs and will require more substantial coordination with the U.S. Coast Guard and regional partners. More information will be shared on this phase of the project in early 2027.
During next week’s three-day closure, the 50,000 daily commuters who rely on the 1st Avenue S. bridge route will be redirected to I-5, a route already dealing with added pressure from the ongoing Revive I-5 project at the Ship Canal Bridge.
Phase 1 is scheduled to wrap up at 8 p.m. on Wednesday, March 11, when all northbound lanes will reopen with a reduced speed limit.
Nate Connors is a traffic reporter for KIRO Newsradio. Follow him on X. Read more of his stories here. Submit news tips here.
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