SR 18 to see full closure this Saturday near Snoqualmie

Highway will be fully closed between Issaquah-Hobart Road and the Interstate 90/SR 18 interchange.

The north end of State Route 18 is expected to be closed in both directions this Saturday, July 23, from 6 a.m. until 8 p.m., according to the Washington State Department of Transportation. The highway will be fully closed between Issaquah-Hobart Road and the Interstate 90 interchange.

Local access will be provided to those who live on Southeast 104th street, just south of the interchange.

That closure will provide maintenance crews and engineering teams behind both the SR-18 Issaquah-Hobart Road to Deep Creek widening project and the I-90/SR 18 interchange improvement project to study and perform maintenance on multiple areas of the highway.

Maintenance crews will repair failing pavement and fill potholes. They also plan to work on highway drainage, guardrail repairs and cut back brush and tall grass to improve sight lines.

The engineering team responsible for the $640 million SR 18 widening project will perform measurements, survey work and take roadway samples. The widening project was approved this year following the passage of the state Move Ahead Transportation package and, among other things, will widen the highway to four lanes between Issaquah-Hobart Road and Deep Creek. Construction on this stretch of highway won’t begin until at least 2025, according to WSDOT.

Contractor crews behind the interchange project, which is slated to begin this year, will also perform inspections, review conditions of existing bridges and do survey work. The interchange project will build a diverging diamond interchange and widen the highway to four lanes all the way to Deep Creek. This project is expected to wrap up in 2025. WSDOT name a contractor for the $190 million project back in January.

Improvements near Maple Valley

Additional delays are expected on the south end of the highway, where WSDOT crews will close the left lane between Covington and Maple Valley in preparation for pavement repair.

Drivers can expect to see crews close the shoulder on SR 18 daily beginning Monday July 18, from 9 a.m. to 3 p.m., until Wednesday, July 20. A nightly lane closure begins on Wednesday, July 20 and continues Thursday, July 21, from 9 p.m. to 5 a.m.

Editor’s Note: This story has been updated to add additional information provided by WSDOT.