1-Myth-Spring weight restrictions last only a month.
Truth: The 47 year average is 64 days, or 9 weeks of spring weight restrictions
2-Myth-Heavy trucks can’t go anywhere because of the spring weight restrictions.
Truth: Weight limitations can make things very problematic—consider a fully loaded concrete truck can weigh in at 72,000 pounds. State and federal roads have pre-posted limits. Some local governments exercise their right to impose further restrictions.
3-Myth-It’s all about the freeze-thaw cycle.
Truth: Well, yes and no. The freeze thaw cycle does wreak havoc—consider overnight lows in the single digits and daytime highs in the 30’s (and pavement temps pushing 50 degrees or more). In reality the other main factor is that the area below the road surface thaws, and moisture in that level cannot drain through the frost below. That thawed material acts like a sponge and moves under the weight of traffic on the road. That movement stresses the road surface and causes damage.
4-Myth-Road limits come on mid-March and come of early May.
Truth: Over the last 47 years, road limits come on anywhere from February 16 to March 24, and come off anywhere from April 10 to May 27.
5-Myth-Springtime posted roads are everywhere.
Truth: Some roads are too weak to withstand legal loads during the springtime freeze/thaw period. There are, however, only about 170 miles of these roads in Wisconsin, or about two percent of all state highways.
6-Myth-Road limit schedules are based on the weather.
Truth: Actually the DOT uses frost tubes to determine how far down the frost is. When the thawed area reaches the subsoils, road limits are enacted.
7-Myth-Weight restrictions are imposed statewide at the same time.
Truth: There are five zones across the state, and weight restrictions are imposed in each zone based on actual determinations of thawing roadways.
For more information on seasonal weight restrictions, visit the state DOT website’s informational portal below.