What Is Black Ice and What Makes It So Dangerous?

Roadway with black ice

Those of us who live in colder climates have experienced black ice at least once. We’re driving along on a dreary winter day, and suddenly our car loses traction. Sometimes we’re able to regain control, but that isn’t always the case.

Black ice is a thin coating of ice that forms on top of roads and pavement. It’s called black ice because it’s highly transparent, so the dark color of the road can be seen through it. It can be tough to spot from behind the wheel of a car and often results in an unexpected loss of traction when driving over it, making it very dangerous and potentially deadly.

In the United States, every year, over 150,000 accidents occur because of ice on the roads, and over 550 people die in these crashes. So, it’s imperative to be fully aware of when, how, and where black ice forms and what to do when you’re caught driving on it.

What Is the Difference Between Black Ice and Regular Ice?

Black ice is not much different from regular ice: it is just frozen water on the road’s surface. How black ice freezes to the pavement is different, though, making it completely clear and hard to spot, especially on dark surfaces at night.

When falling snow and sleet freezes to roads, tiny air bubbles get trapped inside the ice, giving it a cloudier, more translucent appearance. With black ice, those bubbles don’t form, allowing it to freeze clear.

When Does Black Ice Occur?

Black ice occurs when it’s raining, and the low temperature of the ground causes the precipitation to freeze on the road’s surface. Black ice can also happen when the snow melts on roads and refreezes as temperatures drop.

While black ice can form during the day in the shade, it is more common between sunset and sunrise when temperatures drop to their lowest.

At What Temperature Does Black Ice Form?

Black ice typically forms when air temperatures are at or below 32 degrees Fahrenheit (0 degrees Celsius). However, the air temperature doesn’t always need to be at or below freezing for the process to commence. The critical variable here is the temperature of the pavement itself. If the surface temperature of the road is below freezing, even though the air temperature is not, there is still an increased risk of black ice forming.

Where Can You Commonly Find Black Ice?

Watch for ice on bridge warning sign

You will commonly find black ice on roads that are shaded by trees or other objects. It can also be found on back roads, tunnels, overpasses, and bridges. Bridges and overpasses are highly susceptible to black ice as they are elevated, allowing air to pass above and below the surface of the roadway, which causes a bridge’s surface temperature to fall more rapidly when the ambient temperature drops.

How Can You Tell When You Are Driving Over Black Ice?

Driving over black ice isn’t a pleasant experience. Unexpectedly your vehicle will start to lose traction to the road’s surface, and it will begin to slide, your car’s stopping distance and handling will be severely impaired. Attempts to correct the skidding of your vehicle can make the issue worse. If you have anti-skid technology in your car, the light may begin to flash as the car itself attempts to compensate for the loss of traction on its own.

What to Do When You Hit Black Ice While Driving?

Cars driving on icy road

The first thing to remember if you encounter black ice is not to panic. When we panic, we make rash and sometimes unwise decisions. If you hit black ice while driving, the general rule is to stay calm and avoid overreacting, do as little as possible and let the vehicle pass over the ice. Use these steps to regain control:

  • Stay calm, and don’t make any quick adjustments.
  • Take your foot off the gas pedal. Slowing down the car by taking your foot off the accelerator will make regaining control that much easier.
  • Don’t hit the brakes. You don’t want to use your brakes at all, braking can cause the vehicle to slide, especially if you brake too hard.
  • Gently turn into the skid and don’t try and overcorrect your steering. Try and keep your steering wheel straight. However, if your car’s back end starts sliding left or right, turn the steering wheel the same way. The goal here is gentle, gradual movements of the steering wheel into the direction you are skidding. If you try to overcorrect and steer against it, you risk sliding and spinning out.
  • As the car gains traction, gently apply the gas. Once the skidding subsides, and your vehicle straightens and slows down, you will have gained some traction. Gently press the accelerator. Be careful—there may be other black ice patches nearby.

Safety Tips for Driving in Icy Conditions

Remember always to reduce your speed when driving in icy conditions (when temperatures are around freezing). Reducing your speed will give you more control over your vehicle. It’s also essential to keep a safe distance between your car and the vehicle in front of you. A following distance of at least 5 seconds is ideal. Make sure your tires are correctly inflated and have plenty of tread, and lastly, do not drive in icy conditions with your cruise control turned on.

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