Aquaplaning and the road surface

What is aquaplaning?

Aquaplaning means your car slides over a layer of water instead of going through it. Water gets between your tyres and the road. Your tyres can then hardly pass on any steering or braking force. Often the steering suddenly feels light.

What should you do when aquaplaning?

Gently release the accelerator and keep the steering wheel steady in the direction you want to go. Do not brake hard and do not steer suddenly. Your speed will then drop by itself. This lets your tyres touch the road again.

• Gently release the accelerator.
• Steer smoothly and straight, in the direction you want to go.
• Do not brake hard and do not jerk the wheel.
• Tyres gripping again? Drive on calmly, slower than before.

What is the main cause of aquaplaning?

Driving through water too fast. Speed is the factor you control most. The faster you drive, the less time your tyres have to push the water away. There is no fixed speed that is always safe.

When can aquaplaning happen?

When there is water on the road: puddles, a heavy shower and ruts in the road surface. Your tyres matter too. Little tread, the wrong tyre pressure and wide tyres increase the risk.

Do you see puddles or deep ruts? Slow down before the water and keep more distance. You do not need a sign for that. A 100 limit does not mean 100 is safe. You also follow a lower matrix speed or a sub-sign for wet roads.

Which tyres increase the risk of aquaplaning?

Tyres with little tread and wide tyres. The wrong tyre pressure does not help either. Check the pressure when the tyres are cold, following the manufacturer’s advice.

The tread

The grooves in your tyre are called the tread. They carry the water away from under the tyre. If the tread is too shallow, the water cannot get out fast enough. You start sliding sooner.

Narrow or wide tyres?

This is where many people go wrong in the exam:

• Narrow tyres cut through the water more easily. They are better against aquaplaning.
• Wide tyres slide over the water more easily. They give more risk of aquaplaning.

Is a winter tyre better in the rain?

Not always. Summer and winter tyres each give the most grip in their own season. Winter tyres are not required in the Netherlands. For aquaplaning, what counts most is your speed and the tread, pressure and width of your tyres. Which tyre to choose and how much tread you need is explained on tyre tread and summer or winter tyres.

What are ruts in the road?

Ruts (spoorvorming) are shallow grooves in the road surface where the wheels always drive. They are caused by heavy lorries, especially in the right-hand lane. After a shower, water stays in these ruts. That makes aquaplaning more likely there.

Where is the risk of aquaplaning greatest?

In the ruts in the right-hand lane and at puddles. That is where water stays longest. Sign J1 warns of a poor road surface, where water often collects.

Sign J1 (Poor road surface): warns about an uneven or worn road surface — exactly the kind of road where water stays.