If there is a question, we lean toward safety. Road and weather conditions can change very rapidly. The posting of updated requirements does take some time. Nevertheless, obey all posted requirements. Ice Ban, made from corn plants, is so benign you could eat it, with no ill affects.
Calcium chloride can be corrosive to certain soft metals if left on for a period of time.
You should still wash it off regularly, especially if you have untreated aluminum wheels, for example. The DOT wants to provide the safest road surface possible to reduce accidents and injury or death on winter highways. The anti-icer is a tool we use because it works. We still use sand and sand mixed with treated salt because that still works too. Under many conditions, the anti-icer is the best choice to keep a roadway from becoming icy, and to restore it to a bare condition after a snow event.