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Oregon Thanksgiving Travel: Why I-84 Can Stay Icy After Treatment
Portland, OR – Oregon drivers preparing for Thanksgiving travel on Interstate 84 should know that even a freshly treated highway can become dangerously icy. From Portland through the Columbia River Go
By Mason Reid · 2026-11-11T19:36:59.180Z
Portland, OR – Oregon drivers preparing for Thanksgiving travel on Interstate 84 should know that even a freshly treated highway can become dangerously icy. From Portland through the Columbia River Gorge and into eastern Oregon, freezing rain, mountain snow and falling temperatures can create hazardous conditions despite winter maintenance efforts.
According to winter maintenance guidance from transportation agencies, conventional road salt becomes less effective as pavement temperatures approach 20 degrees Fahrenheit. Its ice melting ability declines further in the teens and single digits, although actual performance depends on the material used and road conditions.
Why Treated Oregon Highways Can Still Freeze Road salt and other deicing materials help prevent or remove ice, but they cannot guarantee safe traction.
Around 20 degrees, conventional salt works more slowly than it does near freezing. Below approximately 15 degrees, salt alone may struggle to melt ice quickly enough.
That matters along I 84 through Portland in Multnomah County, Hood River in Hood River County, The Dalles in Wasco County and Pendleton in Umatilla County.
The Columbia River Gorge presents an additional concern: Cold air moving through the Gorge can contribute to freezing rain and ice, sometimes while nearby areas experience ordinary rainfall.
Other routes, including I 5 through Salem, Eugene and Medford, can also become hazardous during winter storms.
Thanksgiving Travel Raises the Stakes Thanksgiving falls Thursday, Nov. 26, bringing holiday travelers onto Oregon's major interstate corridors.
If freezing rain, snow or sharply falling temperatures develop during the holiday travel period, treated highways could remain dangerously slick.
Bridges, elevated ramps and shaded stretches deserve particular attention because ice may persist even after surrounding pavement begins to clear.
The Oregon Department of Transportation uses snowplows and winter road treatments, but no method guarantees ice free pavement.
Drivers should also be prepared for changing conditions near mountain passes and possible traction or chain requirements.
Before departing, motorists should check National Weather Service forecasts and ODOT's TripCheck service for current highway conditions, closures, cameras and travel alerts.
The bottom line: Treated does not mean safe. Reduce speed, increase following distances and never assume a wet looking highway is free of ice.