How Road Icing & Black Ice Hazards Are Evaluated
Winter vehicular accidents frequently trace back to treacherous road ice. Icing hazards can develop even when air temperatures hover at 34–38°F (1–3°C) due to radiant nocturnal ground cooling.
This tool assesses four parameters: air temperature, relative humidity, wind speed, and road surface type. Bridges lack ground insulation, losing heat from both top and bottom surfaces to freeze up to 1.4 times faster than roadbeds on earth.
When pavement temperatures plunge to or below the dew point, transparent black ice coats the road, producing near-zero traction that is virtually undetectable to the eye.
Throughout US interstate highways, mountain passes, and bridge corridors, winter black ice represents a severe driving hazard. This calculator assists motorists in identifying icing risks.