Hydroplaning

Hydroplaning Explained: What It Is and How to Avoid It

Zutobi
by Zutobi · Updated Mar 03, 2022

Most drivers that have driven in heavy rain have most likely experienced hydroplaning even if it was just for a brief moment. You may have felt a sudden loss of control or feedback the moment your tires lost traction. Such situations can seem harmless, but they can easily turn very dangerous unless you know how to react.

What is Hydroplaning?

Hydroplaning is the name of the phenomenon which occurs when a layer of water builds between your tires and the road surface, which causes your tires to lose traction and ‘surf’ on top of the water. People often use hydroplaning as a word to describe driving in slippery and wet conditions, but it refers to the very specific situation when water causes your tires to lose all available traction with the road surface.

car driving in heavy rain
Hydroplaning is more likely to occur if there is a lot of water on the road.

Hydroplaning can be scary and potentially very dangerous as you won’t be able to steer or control your vehicle. In addition, doing the wrong thing (such as braking before you get your traction back) can worsen the potential outcome considerably.

Why Does Hydroplaning Occur?

Hydroplaning occurs when your tires cannot push/remove the water that is on the road fast enough, plain and simple. When you experience hydroplaning, it is almost impossible to control your car until you regain traction. You’ll be experiencing a complete lack of control over your vehicle, which may well lead to an accident.

Below, we’ve illustrated what happens when you hydroplane.

Effect of hydroplaning at different speeds
A) Water is pushed away. B) Water builds up in front of the wheel. C) The wheel “surfs” on top of the water

How to Avoid Hydroplaning

The follow-up question on everyone’s mind is; well, how can I avoid hydroplaning? To answer that you’ll need to know which factors will affect how fast your tires can pump water away from the traction/contact point.

Hydroplaning is usually caused by the following 5 factors:

  1. The amount of water on the road
  2. Tire tread depth
  3. Tire width
  4. Tire pressure
  5. The speed at which you are driving (this is the 2nd most important factor)
the factors that cause hydroplaning

Once you know what to look for and how different factors affect the rate a tire can move water away from the road surface to create traction, you will know what to look for to reduce the risk of hydroplaning.

In fact, depending on the shape of your tires and the speed you are driving at, you may experience hydroplaning even when other cars won’t. Let’s go through why.

Factor #1 – Amount of Water on Road

The most important factor is the amount of water on the road. Even with the best wet tires in the world, you should always take the amount of water and heavy rain into consideration.

The reason is simple, hydroplaning occurs when you cannot push the water between your tires and the road away, which means the amount of water on the road will have the most direct impact.

Factor #2 – Tire Tread Depth

The tire tread depth is simply another way of determining how large your grooves are. The grooves act as the channel which dispenses water away from under the tire. The larger the grooves, the more water they will dispense.

The problem with tire tread depth is that it wears down as you drive. This means a new tire will have larger grooves than a used tire, even if they are both legal to drive. In most states, the minimum legal tread depth is 2/32 inch. If you are close to that limit, consider your tires to function less-than-perfectly in regards to pushing away water.

Are your tires old and worn?

A tire with an adequate tire tread depth will always push away more water than a tire with a tread depth that is less than the minimum level.

Factor #3 – Tire Width

If you think about it, it’s quite logical that the width of the tires will increase your risk of hydroplaning. Wider tires will have to push far more water away due to their size. If you have unusually wide tires, you should be extra careful in heavy rain or when driving through puddles at speed.

Factor #4 – Tire Pressure

Keep your tires properly inflated at all times to reduce the risk of hydroplaning. Overinflated tires tend to reduce grip in most situations, including when wet, and underinflated tires are more prone to hydroplaning as they won’t push away water through the grooves as effectively as they would have had they been inflated properly.

Make sure that your tires are in good shape and have adequate tire pressure. Underinflated tires won’t push away water through the grooves as effectively.

Factor #5 – Your Speed

Speed will affect how long your tires stay in contact with a specific contact point and affect how much water your tires are able to push away. The faster you drive, the harder it will be for your tires to push the water away.

Think of it this way; if the grooves in your tires can pump water away from the road at a certain pace, you cannot exceed the pace or they won’t be able to push water away fast enough.

While it may appear obvious, it bears to repeat. You must reduce speed when the roads are wet. Hydroplaning generally occurs at speeds higher than 50 mph but may occur at speeds slower than 50 mph depending on the shape of your tires and the amount of water on the road.

Higher speed = higher risk of hydroplaning. The faster you drive, the harder it will be for your tires to push the water away.

What to Do When Hydroplaning

If you notice a sudden loss of feedback from your vehicle when you are driving in very wet conditions, you are likely hydroplaning. You should then follow these 5 safety tips:

  1. Focus on keeping your wheels in the same direction as the road so you won’t drive off the road when you get traction back
  2. Not make any sudden turns
  3. Release your gas pedal
  4. Avoid hard braking (if you brake hard, you may lose control over your vehicle)
  5. Keep the clutch pressed down (if manual vehicle)

Once you get traction back, you can then apply the brakes or make the turns necessary to get back in position on the road. The best approach is to wait it out (as you can’t do anything!) and position your vehicle in the best possible position for when you get traction back.

If you attempt to apply the brakes as you hydroplane, what will happen is that you may randomly get traction for a brief moment with one of the wheels and turn your car in the wrong direction.

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