Traffic
Iowa Winter Travel: Salted I-35 Can Still Turn Icy
Des Moines, IA – Iowa drivers preparing for Thanksgiving travel on Interstate 80 and Interstate 35 should know that a freshly salted highway can still become dangerously icy. When pavement temperature
By Natalie Brooks · 2026-11-11T19:19:15.603Z
Des Moines, IA – Iowa drivers preparing for Thanksgiving travel on Interstate 80 and Interstate 35 should know that a freshly salted highway can still become dangerously icy. When pavement temperatures plunge, traditional road salt becomes less effective, leaving slippery conditions even after highway maintenance crews have treated the roadway.
According to winter maintenance guidance from transportation agencies, conventional road salt loses effectiveness as pavement temperatures approach 20 degrees Fahrenheit. Its ability to melt ice slows further in the teens and single digits, making prolonged cold a challenge for winter road crews.
Why Even Salted Iowa Highways Can Freeze Road salt lowers water's freezing point, helping melt snow and ice under suitable conditions. However, it does not guarantee clear pavement or safe traction.
Around 20 degrees, salt melts ice considerably more slowly than it does near freezing. Below approximately 15 degrees, conventional salt alone may struggle to improve icy road conditions quickly.
That matters for motorists traveling through Des Moines in Polk County, Iowa City in Johnson County, Council Bluffs in Pottawattamie County and Davenport in Scott County.
Major corridors including I 80, I 35, I 380, I 29 and I 74 can remain slippery despite treatment, particularly on bridges, overpasses and open stretches exposed to strong winds.
Thanksgiving Travel Could Increase the Danger Thanksgiving falls Thursday, Nov. 26, bringing holiday traffic onto Iowa's interstate network connecting the Des Moines metropolitan area, Cedar Rapids, the Quad Cities and neighboring states.
If snow, freezing rain or sharply falling temperatures develop during the holiday travel period, treated highways could still become hazardous.
Blowing and drifting snow can also cover previously cleared lanes, especially across Iowa's open rural stretches. Wet pavement may refreeze overnight as temperatures fall.
The Iowa Department of Transportation uses plowing and winter road treatments, but no treatment guarantees ice free travel under every condition.
Before departing, motorists should check National Weather Service forecasts and Iowa 511 for updated road conditions, traffic cameras and travel alerts.
The bottom line: Salted does not mean safe. Reduce speed, increase following distances and remain alert for black ice, particularly on bridges and during overnight travel.