Before a storm, we anti-ice the roads by applying a liquid solution to them. This solution prevents snow and ice from binding to the pavement and lowers the temperature that water freezes. The reason we apply a liquid and not solid salt is that the dry salt is blown away or bounces off the roads when applied before precipitation moistens them. Once precipitation begins, we begin to apply rock salt which requires moisture to be effective.
During and after a storm, we work to de-ice the roads. We remove the ice and snow from the surface of the road by plowing and applying additional materials to the surface of the roads. This helps to loosen the ice and snow from the pavement, while also lowering the freezing point of water.
You may also see some materials spread along a cleared highway after a snowstorm. This post-storm treatment is applied to the roads to prevent them from re-freezing during nighttime.
There are 5 types of materials we use to treat the roads for snow and ice,