Essentially, black ice is a thin layer of ice that is nearly impossible to see – other than it might be shiny. It’s called black, but it’s really invisible. I think it occurs most often when you get sleet or melted snow that then freezes when temperatures drop.
You can’t see it but you can suspect it if you have an outside temp guage in your car. When it suddenly drops below freezing and it’s been raining- look out.
Another potentially disturbing thougt. Kentucky had/has the highest rate of uninsured motorists!
What speedz said. A thin layer of ice that is see-through so the black asphalt shows through. You don’t realize you’re on it until your car starts to slide. It catches you by surprise. Most people when they drive on a snow covered road exercise some caution and go slowly. You usually will have no control of your vehicle. It happened to me one night driving on a backroad to the gym. Dark road with not many street lights. Going about 35 mph. Within half a second, I went from driving straight ahead into a sideways slide for about 30 yds, across the opposite lane onto someones front yard.
Usually when you get melting snow during the day on a flat road with no crown in the middle. The snow on the sides of the road melts and flows onto the street. The water lays in the middle or off to one side. The water freezes at night and the trouble begins. Sometimes the ice is so thin it doesn’t shine and is only thick enough to cover the rough surface of the asphalt.
Black ice = invisible thin coating of ice on the road. If you’re not paying attention to a temperature gauge, or you don’t have one, then the first you will know about it is when you are sliding sideways. If the road’s gritted, you’re safe. If you’re on a little country road, and it might be icy, play safe, drive slow. The clasic black ice accident is the one where you drive down a nice ice-free lane midmorning, air temperature just above freezing, get to a corner and the hedge blocks the sun, suddenly you’re on ice and in the ditch.
You’ll occasionally see a sign up - ‘BLACK ICE’ in a red triangle over here - warning about it in nasty spots. In the middle of woods, in a dip, where the road’s not cambered are places where you might have problems.