Heavy traffic is being reported on a 10-mile stretch of northbound Interstate 5 from DuPont to Lacey.
The state Department of Transportation said weekend travel is resulting in slowdowns and backs from milepost 119 to milepost 109.
Drivers are warned to avoid the area if possible.
UPDATE as of 8:55 p.m.
WSDOT reports that traffic is moving at a normal pace.