What does a 'shiny' patch of road in winter typically indicate?

A 'shiny' or 'wet-looking' patch of road in freezing conditions is one of the strongest visual indicators of black ice. Black ice is a thin, transparent layer of ice that takes the color of the pavement beneath it, making it appear to be wet road. It forms most easily on bridges, overpasses, and shaded sections of road, especially in the early morning before sunlight has had a chance to warm the surface. If your spray from the wheels suddenly stops in cold weather, it likely means the road has frozen and you should slow down without sudden steering or braking. Don't trust ambient temperature alone; the road surface can be below freezing even when the air is 35 degrees. Bridges freeze before the rest of the road because cold air flows under them as well as over.