Currently, to combat slippery icy roads state officials spread salt over the roads but this technique can be futile as it washes off with ease, forcing reapplications while other anti-icing agents pose as potential threat to the environment with their harmful chemicals. However this method of mixing these agent into the asphalt sustain safety for longer amounts of time (potentially years on active roads) while not harming the environment.
The photo below compares new asphalt composites to old, the new compound (right) slows down the development of ice and you can view there is less ice collected on the surface, where the conventional materials (left) have already collected some icy formation.