Why do pavements buckle?
The heat factor
Pavement buckles can occur when the air temperature changes from moderate to extreme heat. When a road is constructed it is cut into segments creating a space for expansion and contraction. Sometimes that space is not enough and when that happens the pavement buckles or blows up, particularly when the pavement is older and weaker. The warmer the temperature the more the pavement material expands. The sun heats the pavement, and the pavement expands and then buckles. Buckles more commonly occur on older concrete pavements.
Blacktop (bituminous) pavement is a more flexible material and does not usually blow up but may create a bump similar to a frost heave, especially in areas where concrete and blacktop meet.
When buckles occur, they become a MnDOT priority. Crews who are patching or mowing are reassigned to fix the pavement buckles. Please be patient with workers and other motorists on the road.
What do I do if I come across a buckle?
Pavement buckles can be very dangerous for motorists. Try not to drive over a buckle if possible. Instead, slow down and safely move into another lane. Call 911 if you encounter one.
Example
Hwy 36 in Little Canada, June 2016
Note the pavement buckle on the closest lane of traffic driving towards you.