General

What is black ice?

Black ice can be very dangerous, so it is important to know what it is and how you should react if you have an encounter. The most basic definition of black ice is a thin coat of highly transparent ice. The reason it is transparent is that it blends in with road pavements since it is so thin, making it nearly impossible to see. Its called black ice since it looks black, like the color of the road pavement it forms on.

What causes black ice?

If the temperature rises above freezing or the sun comes out during the day, any snow on the ground will slowly melt and cause road surfaces to become wet. If it rains, that could also lead to wet roadways with some puddles. If the temperature then drops below freezing while the ground is still wet, black ice will likely form on paved surfaces due to the refreezing.

Common locations to find black ice include bridges, overpasses and spots on the road shaded by trees or other objects. Bridges and overpasses are prone to black ice because cold air is able to flow underneath the road surface, since it is elevated, therefore lowering the pavement temperature. Shaded spots on the road are prone since they receive less warmth from the sun during the day.

Why is black ice dangerous?

Since black ice is highly transparent, it is unlikely you will be able to see it while driving down the road. Roadways become very slippery when black ice forms, leading to hazardous driving conditions and an increased risk of car accidents.

Here are a few tips that may help if you are caught in areas of black ice:

  • Keep your steering wheel straight. If you turn the wheel, you have a better chance of sliding and losing control of your vehicle.
  • Do not brake. Braking causes the vehicle to slide, especially if you brake too hard.
  • Take your foot off the accelerator to reduce speed. It is best to let the car stop on its own if you have enough room in front of you.

Source: https://weather.com/science/weather-explainers/news/black-ice-winter-weather-explainer