Iowa DOT News Release

Wheel track glazing causes travel hazards on Iowa roadways today

Posted on: January 29, 2009

AMES, Iowa – Jan. 29, 2009 – The combination of light snow and cold surface temperatures could result in icy roadways due to a phenomenon called wheel-track glazing.  Wheel-track glazing is caused by warm tires trapping the ground-level blowing snow. As more vehicles travel over the same wheel tracks a glaze of ice forms, which becomes very slippery. The condition is very difficult for Iowa Department of Transportation (DOT) crews to treat, as the ice is continuously forming on heavily traveled roadways.

Saving lives and preventing the risk of serious injury under these conditions requires:

  • A basic understanding of the conditions that contribute to wheel glazing.
  • Access to current road weather information.
  • The exercising of good judgment.
  • Adherence to simple safety tips.

The Iowa DOT developed a Web site ( that includes winter safe driving tips and information, images and a video about the causes and possible consequences of driving in conditions that may create wheel track glazing.

Safety tips

Here are some tips for driving on icy roads, if necessary:

  • Take it slow.
  • Give your full attention to the driving task. Don’t talk on the cell phone or text message while driving.
  • Do not use cruise control.
  • Put a safe distance between your vehicle and the other vehicles sharing the roadway.  
  • If conditions are severe enough to prevent safe driving, postpone your trip, or if enroute, identify the nearest safe place to pull off the roadway, such as a rest area, truck stop, motel or other traveler service until the wind subsides and road conditions improve.
  • Keep your windshield clear of ice and turn on your vehicle’s lights.
  • Allow extra travel time.
  • Plan ahead by checking for the latest road conditions.



Contact: Dena Gray-Fisher at 515-239-1922 or


Iowa highway in the evening