Originally Posted by
tjspiel
Rime ice is different. You'll set it on chain link fences, trees, etc. I'll see it on my person too from my breath freezing. Black ice on streets from car exhaust doesn't look like that at all. Maybe it would if left to itself but it's getting constantly driven over.
No, rime ice isn't different. It is, essentially, ice that forms from the gaseous form (aka water vapor) to the solid. It's the opposite of sublimation.
If water vapor from car exhaust could form "black" ice, it would form it using the same mechanism passing from vapor to solid without going through the liquid phase.
Originally Posted by
tjspiel
You also have to remember that morning commutes in the winter often occur before sunrise or just after it. Lighting is low and uneven. There are shadows. The roads themselves typically have a grayish hue from salt residue and will be darker in some places and lighter in others. You can see black ice when your eyeballs are 6 inches away, but it's pretty easy not to recognize it as ice when further away.
You are going to have to try harder than that. I wasn't born at night nor was I born last night. I've seen enough ice to know that ice isn't invisible any any of its forms...unless it isn't there.