Ask a Trooper: Law requires removal of frost from auto windows


Question: The other day at an intersection I noticed a car with the windows so frosted up that the driver had to roll down a window to check for cars coming from my side. What is the law on frosted windows?

Answer: Minnesota state law says that no person shall drive any motor vehicle with the windshield or front side windows covered with steam or frost to such an extent as to prevent proper vision.

While the statute does not mention rear windows, I highly recommend that all windows be cleared. Too many people remove the snow from the windows, but leave it piled high on the engine hood.

If all of the snow and ice is not properly removed, it can be blown from the vehicle when highway speeds are reached. Snow and ice can also be sucked into the fresh air intake of your vehicle (normally located near the bottom of the front windshield) usually resulting in moisture fog on the inside of your windows and windshield.

To ensure proper visibility, be sure to clear all snow and ice from your vehicle. Taking the proper steps could help you avoid a crash.

A portion of state statutes were used with permission from the Office of the Revisor of Statutes. If you have any questions concerning traffic related laws or issues in Minnesota, send your questions to Sgt. Neil Dickenson, Minnesota State Patrol, 1131 Mesaba Ave., Duluth, MN 55811. You can follow me on Twitter @MSPPIO_NE or reach me at