SR 99
Route ID
099
Start planning now: Major highway closures, lane reductions around Puget Sound Oct. 11-14
Update: Oct. 10, 2024 - I-5 lane closures in Seattle will now include northbound lanes between mid-Boeing Field and the West Seattle Bridge. The updated information is reflected in the release below.
Update: Oct. 9, 2024 - The hours for the I-405 overnight lane reductions and ramp closures have changed. Note the lane closures will occur 8 p.m. Friday, Oct. 11 to 8 a.m. Saturday, Oct. 12. Ramps will be closed from 11 p.m. Friday to 8 a.m. Saturday. This updated information is reflected in the release below.
SR 99 tunnel to close for first two weekends in October for inspection in Seattle
SEATTLE – Both directions of the State Route 99 tunnel in Seattle will close the first two weekends in October for its first six-year inspection. The tunnel opened to travelers in February 2019 to replace the Alaskan Way Viaduct and provide safety and mobility improvements along Seattle's central waterfront.
Closure details
From 10 p.m. Friday, Oct. 4, until 6 a.m. Saturday, Oct. 5, and from 10 p.m. Friday, Oct. 11, until 6 a.m. Sunday, Oct. 13, both directions of the SR 99 tunnel will close.
Update: Overnight ramp closures, detours at I-5/SR 18 interchange May 3-5 and May 2 on SR 509
UPDATE: Work rescheduled for week of May 1
FEDERAL WAY – Evening travelers in south King County should add additional time or adjust routes the week of May 1 for ramp and/or lane closures in two locations, including State Route 509 and the Interstate 5/State Route 18 interchange in Federal Way.
Slow down on ice and snow.
It's easier to skid or lose control traveling at higher speeds. Give yourself more time to stop.
Carry chains, practice installing them.
Winter conditions could mean chains are required on your route. Practice putting them on your vehicle ahead of time.
Pack your winter car kit.
Carry extra supplies like warm clothing, ice scraper and brush, jumper cables and other emergency items.