Ask A Trooper

Sgt. Jesse Grabow

Question: Last week, I noticed a truck with a snow plow blade on it, it took up the whole traffic lane, it was not a Minnesota Department of Transportation truck.  What is the legal length allowed for a snow blade?

Answer:  The maximum legal width is 8 feet 6 inches in Minnesota.  Snow plows start at widths of 6 ½ feet for smaller pickups and go up to 9 and 10 foot wide plows for dump trucks.  The most common size plow if 7 feet and 6 inches.  If you are over 8 feet 6 inches you can apply for a permit through the state.  The permit will allow you to transport the plow on the roadway. 

You can avoid a ticket—and a crash—if you simply buckle up, drive at safe speeds, pay attention and always drive sober. Help us drive Minnesota Toward Zero Deaths.

Question: Are yellow speed signs in curves or busy locations enforceable? I’ve seen 60 mph white speed limit signs then a short distance later a yellow 50 mph sign. The yellow signs don’t say “limit” on them, so I would think going 60 mph in a yellow 50 mph zone isn’t illegal but not a good idea.

  Answer: The white signs are regulatory signs. Yellow signs are warning and advisory signs. You could see the yellow signs in areas such as curves, winding roads, etc. to help inform motorists about what is safe.


Red: Prohibits and commands

White: Regulates


Yellow: Warns

Yellow-green: Warns and controls pedestrian and bicycle crossings and school areas

Orange: Warns and controls in construction zones


Green: Guides and informs

Blue: Describes services for motorists

Brown: Indicates historic, cultural, or recreational sites

  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 Trp. Jesse Grabow – Minnesota State Patrol at 1000 Highway 10 West, Detroit Lakes, MN 56501-2205.  (You can follow him on Twitter @MSPPIO_NW or reach him at,