Black ice is a significant driving hazard in winter driving conditions. Black ice consists of a thin layer of ice across the surface of the road. Black ice is called “black” because it is difficult to see, unlike a “white frost”, which is much more visible. Parts of the road that are likely to experience black ice are sections of the road that are shaded throughout the day, which does not allow the sun to melt the frost, and bridges, where the airspace beneath the bridge allows the tarmac to cool. Black ice also occurs during light frosts.

Black ice is more treacherous than a white frost. This is because it is hard to see and the driver may not know that they are on the black ice until they experience sliding or other loss of control. It is not impossible to drive safely on ice – it is possible for a car to be driven on a frozen lake with standard road tyres (if the ice is thick enough) with no loss of control. However, as black ice cannot be seen, the driver does not know to adapt his/her driving style in anticipation of the slippery conditions. This can result in the car sliding out of control and possibly having a collision. This is particularly likely, as corners are often shaded, making perfect conditions for black ice to form.

Road conditions must always be taken into consideration when choosing your driving style. If the conditions are likely for black ice to form, a driver should always be alert for the possibility of black ice and treat all shaded areas, bridges and corners as if they were icy. In a nutshell, if you feel the bite of winter in the air, then expect black ice and drive accordingly.
We hope that helps answer the question ‘What is What is Black Ice?’!

Back to Car Glossary