Pavement repair project on SR 18 and ramps across King and Snohomish counties begins Sept. 11

MAPLE VALLEY – A project to repair and preserve pavement beginning work in mid-September will improve the driving surface along a 5-mile section of State Route 18 east of Maple Valley and at on- and off-ramps across King and Snohomish counties.

Contractor crews working for the Washington State Department of Transportation will seal cracks and make pavement repairs, creating a smoother ride and extending the lifespan of roadways at 15 locations in King and Snohomish counties. Work will begin Monday, Sept. 11, on SR 18, before the project takes a winter pause and resumes next spring to improve on- and off-ramps at the remaining 14 locations in King and Snohomish counties.

The repairs on SR 18 will require all lanes in each direction to close for up to three nights, though eastbound and westbound lanes will not close at the same time.

SR 18 closures

Between 11 p.m. and 4 a.m. nightly beginning Monday, Sept. 11, all eastbound lanes of SR 18 will close near Issaquah-Hobart Road Southeast to just south of Raging River (mileposts 21 to 26). Work on eastbound lanes is expected to take up to three nights, before crews will swap and close all westbound lanes of SR 18 for up to three additional nights to make similar repairs.

Nightly work will continue from 11 p.m. to 4 a.m. Mondays through Fridays until it is completed. Signed detours will be available for both directions of travel, but people should expect delays and consider alternate routes.

SR 18 detours

  • Eastbound SR 18: Follow Issaquah-Hobart Road Southeast north to Front Street in Issaquah and use the on-ramp to eastbound Interstate 90.
  • Westbound SR 18: Follow I-90 westbound to the Front Street exit in Issaquah and head south to Issaquah-Hobart Road Southeast and SR 18.

People traveling in the area also should expect nightly work that is part of the I-90/SR 18 Intersection Improvements project. Between 9 p.m. and 5 a.m. Mondays through Fridays, flaggers will alternate SR 18 traffic just south of I-90.

About the crack sealing project

In addition to the crack sealing on SR 18 in September, the $2 million project will return in spring 2024 to make pavement repairs at 33 on- and off-ramps in King and Snohomish counties. Repairs are planned on:

  • Nineteen ramps at five interchanges along I-405 in Tukwila, Kirkland and Bothell.
  • Three ramps at two interchanges along SR 509 in SeaTac.
  • Eleven ramps at seven interchanges along SR 99/SR 599 in Tukwila, Seattle and Edmonds.

That work will require nightly lane and ramp closures, most of which will last only one night at each location and none longer than three nights. Signed detours will be available for closed ramps.

Real-time travel information is available via the WSDOT mobile app, the WSDOT Travel Center Map, or by signing up for WSDOT’s email updates.

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