Thanks for the link, I do not know it before :-) On de-icing: you can have clean road if they are heavy used together with a not so cold climate since car's it

Thanks for the link, I do not know it before :-) On de-icing: you can have clean road if they are heavy used together with a not so cold climate since car's itself contribute a bit on cleanup phase but you practically can't on any less frequented road, especially outside cities. Salt and gravel help avoiding ice with a "liquid top" that's super slippery but can't really melt snow on snowy days or cold days...