All lanes of eastbound I-90 at East Mercer Way were blocked Thursday at approximately 3:30 p.m. following a semi-truck fire.
One lane had reopened by 4:07 p.m., and by 4:20 p.m. and there was a six-mile backup.
The eastbound I-90 express lanes were open.
WSDOT urged drivers to take SR 520 or go around Lake Washington by taking I-5 to I-405 or SR 522.
Washington State Patrol Trooper George Englebright said the fire started as a blown tire and then spread to the truck's trailer. The trailer will have to be cut up and put on a flatbed trailer, he said.
There were no injuries.