Local Information

Additional repair work planned for US 101 near Cosi Hill in Grays Harbor County this month

Monday, August 2, 2021 - 10:05

Tina Werner, communications, 360-704-3270

Safety work will restore two-way traffic

COSMOPOLIS – Repairs will soon be underway on a slide-prone section of US 101 between Aberdeen and Raymond. By spring 2022, two-way travel will be restored once again to the popular freight corridor.

On Monday, Aug. 16, Washington State Department of Transportation contractor crews will begin work to stabilize the hillside near milepost 78.

How did we get here?

Since January of 2020, this stretch of US 101, referred to as “Cosi Hill,” has been reduced to single lane with a temporary traffic signal due to chronic roadway settlement. The roadway sits on a pre-historic landslide. Heavy rains triggered the highway to drop more than five feet. With the alternating traffic, there are long delays for travelers.

A proven approach to a long-term fix

WSDOT conducted a thorough investigation of the site. Because of the frequency and severity of slide activity, a careful approach was required. WSDOT hydraulic, geotechnical and transportation experts collaborated to produce a solution that would withstand significant movement after heavy rains.

“Our crews will place 45 steel beams up to 43 feet into the ground to form what engineers call a ‘soldier pile wall,’” said WSDOT Project Engineer Karen Boone. “This is when the steel beams are lined up one-by one to imitate a line of soldiers.”

WSDOT implemented this solution in a previous slope stabilization project in 2015 along US 101 at Rock Crusher Hill.

The $5.8 million slope stabilization contract was awarded to Quigg Bros, Inc. earlier this summer.

Keeping people moving

Travelers can expect to see weekday daytime construction. A temporary signal will alternate people, which is currently in place, through spring 2022. Any highway closures will be announced in advance. No work is currently scheduled for weekends or holidays.

Grays Harbor County travelers are encouraged to sign up for email updates. Real-time traffic information is available on the WSDOT app and WSDOT regional Twitter account.

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