If you're traveling over the Cascades on I-90 this holiday season, the worst traffic will be on the day after Christmas and the day after New Year's. The most congested hours will be between 3 p.m. and 6 p.m. You can find better times to travel by checking the Washington Department of Transportation traffic volume charts.
WSDOT also has information on holiday traffic congestion on other major routes.
WSDOT officials say you should be prepared for wet weather and snow in the mountain passes.
