Detours today on Highway 169

An unstable slope showing signs of weakness under the Green River Bridge on Highway 169 near Enumclaw will force the closure of the bridge from 6 a.m. until dark, about 10 p.m., today for an emergency inspection and repairs.

Drivers should expect closures, delays and detours while geotechnical experts drill under the southbound lanes to assess the stability of the ground.

Highway 169 will be closed to all traffic between Southeast 400th Street and Auburn-Black Diamond Road, north of Enumclaw.

Trucks and passenger vehicles can take a seven-mile-long marked detour route that passes west of Highway 169. The state Department of Transportation projected the detour route will add 5 to 10 minutes to vehicle trips.

The detour is expected to particularly affect drivers traveling between Black Diamond and Enumclaw.

By tonight, the bridge will likely reopen to one lane of signalized alternating traffic with a reduced speed limit.

An emergency contractor should be working on interim repairs by as early as next week. Preliminary estimates are that the road will be completely closed for up to two weeks for interim repairs to improve its stability.

In the long term, the Transportation Department said, the entire unstable area next to the highway will need a wall constructed alongside it.