Black ice, to be specific, which is actually not black at all but quite transparent. When the temperature hovers close to the freezing point, roads can acquire small-but-deadly patches of very thin ice. These tiny pockets of antigravity are virtually indistinguishable from the surrounding road surface — until you happen to drive over one, and discover that your brakes and steering no longer work. If it weren't for my cat-like reflexes, I'd be blogging to you from beyond the grave right now.
wide awake now thanks 
