Update, 7:30 pm: They're free!

Original post, 4:38 pm: Thousands of people are still stuck in traffic westbound on Interstate 84 between Hood River and Cascade Locks, nearly 15 hours after the highway was blocked by trucks that lost control on iced-over roads. The backup is about 20 miles long.

The Oregon Department of Transportation says there is not yet an estimated time for reopening the highway. Traffic has been cleared from milepost 46 to 49, and work is currently underway to clear mileposts 49 to 54. Ploughs, de-icers, and salt have all been used so far in an attempt to clear the road, but stuck tractor-trailers are a problem of their own and are taking hours to clear out.

The challenges facing ODOT include no viable exit routes along the 20-mile stretch of highway in the Columbia River Gorge, meaning that once people got stuck in the gridlock there was no way for them to get out.

Traffic has in the last hour begun inching forward, says WW's news partner KATU-TV.

Oregon State Police were passing out food and water to stalled drivers on Wednesday morning, but running out of gas and lack of access to restrooms are still a problem for those stranded.

Many are blaming semi-trucks that didn't chain up for the icy weather, even though ODOT put out a chain requirement Tuesday afternoon when the jam first started. This is the third day in a row that parts of Interstate around the gorge have been closed.