The Washington State Department of Transportation has warned that drivers should expect long delays on westbound I-90.

Traffic is backed up across Mercer Island due to a collision blocking the three right lanes of westbound I-90, near Rainier Avenue South at mile post 3. The backup is six miles long.

A semi-truck transporting French fries rolled over at 2:15 p.m., Wednesday.

Medical aid, fire assistance, the incident response team, tow assistance, and the Washington State Patrol are present at the scene.

For updates, go to the WSDOT website.