Minnesota Department of Transportation

511 Travel Info

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Dec. 23, 2013

MnDOT plow removing snow off two-lane hwy

Black ice, refreezing create dangerous driving conditions

ST. CLOUD, Minn. – The Minnesota Department of Transportation warns motorists that current and forecasted temperatures create conditions for black ice, an invisible hazard that catches drivers off-guard and causes crashes.

Black ice creates the appearance of a wet surface, but it is actually a thin, clear layer of ice on roads and bridges. Black ice forms when melting snow refreezes or when rain, drizzle, mist or fog freezes. It is most common at night and very early morning when it is dark and temperatures are lowest. 

Black ice and refreezing often occur on overpasses and bridges and near lakes and rivers, and in shaded areas. The hazards can also form when snow temporarily melts from auto exhaust emissions or tire heat as well as from moisture vapors given off by industries located close to the highway.

Motorists should remember to:

  • Slow down on all roads in the early morning when the air temperature rises faster than the pavement temperature. Be especially cautious on bridges and overpasses.
  • Use a safe speed for winter driving conditions, regardless of the posted speed limit.
  • Keep a safe stopping distance from the vehicle in front of you.
  • Keep both hands on the steering wheel, both eyes on the road and attention on your driving.

For updated information on road conditions, visit www.511mn.org or call 511.

For additional tips on snowplow safety, go to www.mndot.gov/workzone.


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