WSDOT Issues Urgent Travel Warning: Massive I-5 Closure Triggers Hours-Long Delays for Puget Sound Drivers

Seattle drivers face another week of congestion as the Washington State Department of Transportation (WSDOT) keeps all northbound lanes of State Route 99’s First Avenue South Bridge closed through 11:59 p.m. Friday, March 13 while crews finish emergency repairs. Why the closure was extended Initial inspections revealed cracked steel deck grates; once work began Monday, crews uncovered “more extensive” damage that requires precise realignment where the two bascule spans meet, according to WSDOT. Welding new steel plates over weakened panels will stabilize the structure so traffic can safely resume at a temporary 25 mph speed limit. Detours and travel tips • Northbound SR 99 traffic must exit at Cloverdale/South Park. • Use I-5, I-405 or the South Park Bridge as alternate routes. • Allow extra time during the morning and evening peaks; Monday’s commute saw significant slow-downs across Seattle’s industrial corridor. • Freight haulers should plan overnight moves when volumes dip. What’s next for the First Avenue South Bridge 1. Phase 1 (now): emergency stabilization, reopening all lanes by March 14. 2. Phase 2 (mid-to-late April): full replacement of nine failing grate panels, likely requiring additional weekend closures. 3. Phase 3 (2027): complete northbound deck replacement, part of Governor Ferguson’s proposed $1.1 billion bridge-preservation package. Why this matters The 70-year-old double-leaf bascule bridge carries more than 110,000 vehicles daily and is a freight lifeline between Seattle’s ports and the Kent Valley. WSDOT notes the structure is operating beyond its intended service life, underscoring statewide funding needs for aging bridges. Stay updated • Check the WSDOT app and real-time travel map before you leave. • Follow @wsdot on X and Facebook for live alerts. • Sign up for email or SMS bridge notifications on the WSDOT website. Bottom line Expect heavy traffic on I-5, surface streets in Georgetown and South Park, and variable drive times through Friday evening. Planning ahead and staying informed are the best ways to avoid the worst of Seattle’s latest WSDOT closure.