Originally Posted by
Hypno Toad
It is damn hard to see (it is not white at all) and the uninitiated/inattentive will be caught off guard - and at the wrong time, when your hitting the brakes for a red light.
Any experienced winter cyclist should expect black ice, it common sense that winter will produce black ice when you least expect it. Even if you don't see the black ice at least take some precautions and be prepared for it. Don't slam your brakes hard at the last second and don't take corners at crazy insane speeds when there is a risk of black ice or when the road conditions are slick.