Testing ice for thickness is a very simple process. Be sure you test in several different spots before you drive your vehicle on the ice. Be sure and watch for warm springs, creek outlets and inlets, and other areas of thin ice. Be sure and have at least 12" of good black ice for cars and pickups, 24" to 36" for larger rigs. Refer to the Blog dated 11/13/09 for the ice thickness formula put out by the Corp of Engineers. Above all, be careful!!