", it is clear that ice at ~0° C is vastly more slippery than at, say, -20°C." There is nothing more slippery in my experience, than rain on the street, that j

", it is clear that ice at ~0° C is vastly more slippery than at, say, -20°C." There is nothing more slippery in my experience, than rain on the street, that just turned frozen. But ice at -20°C is usually older and has not such a smooth surface anymore, so hard to compare in non lab settings.