What Is Hydroplaning, And What Should You Do If It Happens?

You're driving in heavy rain, and suddenly your steering wheel goes light. For a moment, it feels like your car is floating on water. You've just experienced hydroplaning. 

Also known as aquaplaning, hydroplaning occurs when a layer of water on the road comes between your car's tires and the road surface, causing you to lose traction and momentarily making your car feel like a boat. Traveling on a film of water also causes you to have limited control over your car's steering and brakes.

Let's break it down. Your car's only points of contact with the road are your tires, which grip it via grooves or tread patterns on their outer surface. The treads also act as channels to disperse water when you're driving on wet roads. However, if you're going too fast, the tires are rotating faster than the rate at which they can disperse water. This causes them to drive on the water surface on the road instead of cutting through it. Hydroplaning can last for a moment or several seconds, but that time is enough for you to lose control and crash into a guardrail or another car.

A lot of factors can cause hydroplaning. Pools of water collecting on the road due to a sudden downpour or improper drainage are common culprits. Even a tenth of an inch of standing water can cause hydroplaning. Driving fast in the rain also increases the chances of hydroplaning. If the tires are spinning faster than the time it takes for them to evacuate water between the grooves, excess water can accumulate between the tire-contact patch and the road. You don't even have to be very fast. Hydroplaning can happen at speeds as low as 35 mph, depending on the weather, the road, and the condition of your tires. Bald tires can easily cause hydroplaning. (Of course, your tires may expire before they wear out.)

But there are ways to prevent hydroplaning. For one, slow down while driving in rainy weather. Driving at a lower speed helps you spot puddles more easily and slow down in time to be safe. If you can't avoid standing water, reduce your speed before passing through it. Also, avoid using cruise control as, with it on, you won't be able to slow down immediately. 

Having good tires is important, too. Ideally, your tires should have a tread depth greater than 2/32 of an inch for water to properly disperse water. And ensure they are properly inflated, as improper tire pressures increase the chances of hydroplaning. Besides all this, it helps if you know some wet weather driving tips.

If you miss all the signs and your vehicle starts to hydroplane, try to keep a cool head. Panicking will only have you go hard on the steering and brakes, which is the opposite of what you should do. 

Get your foot off the gas pedal, but don't slam on the brakes. If your tires are pointing in a different direction from the front of your car, slowly correct your steering to point the tires in the direction the car is moving. Now wait as your car slows down to the point where you regain control and cross the standing water. 

Then take a deep breath. Hydroplaning can be a nerve-wracking experience, and after a hydroplaning event, it's a good idea to take a break to calm your nerves. However, knowing what to do will help you avoid getting into such a situation — and, if necessary, get out of it.