Iowa DOT News Release

Wheel-track glazing causes travel hazards on Iowa roadways today

Posted on: January 06, 2015

AMES, Iowa – Jan. 6, 2015 – The combination of light, blowing 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 light, blowing snow. As more vehicles travel over the same wheel tracks, a glaze of ice forms that becomes very slippery. The condition is very difficult for Iowa Department of Transportation crews to treat because 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-track glazing.
  • Access to current road weather information.
  • The exercising of good judgment.
  • Adherence to simple safety tips. 

See the Iowa DOT’s website to learn more about the formation of the roadway glaze and its consequences. 

Increased driving risk

For drivers, the consequences of wheel-track glazing can be serious; stopping distances are 10 times greater than on dry pavement and double that of packed snow. 

Safety tips

Here are some tips for driving on icy roads, when travel is necessary. Postpone your trip if possible.

  • On “Ice and Snow … Take It Slow.”
  • Give you full attention to the driving task. Do not use a mobile communication device while driving.
  • Turn off the vehicle’s cruise control.
  • Put a safe distance between your vehicle and others sharing the roadway.
  • Keep your windshield clear of snow and ice.
  • Turn on your vehicle’s lights.
  • Allow extra travel time.
  • If you are starting to skid, tap the brakes. Do not push down and hold the brake pedal. 

To discover all the ways in which you can receive around-the-clock Iowa traveler information, visit


For media access to an Iowa DOT Highway Division spokesperson during this winter event, call 515-233-7960.


Iowa highway in the evening