Travelers in the Puget Sound region should prepare for delays and road closures this weekend as construction takes place across I-405, State Route 99, and Interstate 5.
The scheduled work spans the region’s three primary north-south corridors in Seattle and Kirkland. Transportation officials advise drivers to plan for extra travel time, consider public transit and park-and-ride options, and check traffic conditions before leaving.
I-405 in Kirkland
On I-405 in Kirkland, the northbound and southbound ramps at Northeast 85th Street will close from 10 p.m. Friday, Aug. 14, to 5 a.m. Monday, Aug. 17. Northeast 85th Street will also be closed between Sixth Street and 120th Avenue Northeast while crews grade pavement and install curbs as part of an ongoing project.
Detours will be in place.
SR-99 and Seattle ramp closures
In Seattle, the SR 99 tunnel will close in both directions overnight from 10 p.m. Friday, Aug. 14, to 6 a.m. Saturday, Aug. 15, for routine maintenance.
Northbound SR 99 will then close at the First Avenue South Bridge from 5 a.m. Saturday, Aug. 15, to 11:59 p.m. Sunday, Aug. 16, for bridge preservation. Drivers will not be able to access East Marginal Way or Michigan Street from the First Avenue South Bridge during that closure.
Several additional ramp connections in Seattle will also be closed over the weekend. These include the Occidental Avenue South and South Kenyon Street connection to northbound SR 99, the West Marginal Way South and South Holden Street connection to northbound SR 99, and the First Avenue South connection to northbound SR 509.
Revive I-5
The closures are happening at the same time as the Revive I-5 project, where northbound I-5 in Seattle is reduced to two lanes across the Ship Canal Bridge. Express lanes will remain open in the northbound direction 24 hours a day to assist with traffic flow.
The two-lane configuration on northbound I-5 across the Ship Canal Bridge is scheduled to remain in place through the end of 2026. The Harvard Avenue on-ramp to northbound I-5 will remain closed until mid-October.
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