Local Guide

WSDOT Warns of One of Summer’s Busiest Construction Weekends Across King County

Seattle Today Newsroom
August 9, 2026
Picture Credit: Tom Shamberger

The Washington State Department of Transportation has described this weekend as one of the busiest construction stretches of the summer, with closures affecting I-405, I-5, SR 520 and SR 202 along with several local roads across King County. Most begin Friday and run through Monday morning. The surge follows a pause in work during the FIFA World Cup matches held in June and July.

The largest single impact is a full closure of northbound I-405 between North Southport Drive and Coal Creek Parkway Southeast, from 11:30 p.m. Friday until early Monday. Crews will excavate drainage crossings, replace pavement and shift traffic as part of a widening and toll-lane project, and WSDOT has warned of heavy congestion approaching Renton. In Kirkland, both northbound and southbound ramps at Northeast 85th Street close from 10 p.m. Friday until 5 a.m. Monday, along with Northeast 85th between Sixth Street and 120th Avenue Northeast, while work continues on a roundabout and bus rapid transit station.

The SR 520 bridge stays open, but eastbound lanes from I-5 to Montlake Boulevard close from 7 p.m. Saturday until 11 a.m. Sunday for expansion joint repairs. Further east, SR 202 in Fall City closes just past the SR 202 and SR 203 roundabout from 5 a.m. Friday until 9 p.m. Monday while crews rebuild an embankment along the Snoqualmie River, with detours routing traffic onto I-90.

Compounding the disruption is ongoing work on the I-5 Ship Canal Bridge, where lanes are reduced to two in each direction through the end of the year. Officials expect the I-405 closure to push traffic onto I-5, and warned that the SR 520 closure combined with downtown events could back up the eastbound I-90 bridge on Saturday night. Drivers are advised to allow extra time and anticipate delays in unfamiliar places, with conditions likely to shift week to week as projects progress.

ST
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