A damaging landslide has prompted the closure of one lane on state Highway 501/Pioneer Street near Ridgefield, according to the Washington State Department of Transportation.
Starting Wednesday night, a temporary signal began alternating traffic on a single lane between Reiman Road and Smythe Road, according to WSDOT.
Vehicles will use the westbound lane only while crews determine the extent of damage caused by a Dec. 30 landslide.
The eastbound lane will remain closed until workers complete permanent repairs early this year, according to WSDOT.
Last week, WSDOT announced a temporary speed limit reduction along the same stretch of the highway. The agency lowered the speed limit from 40 mph to 25 mph.