How to prevent aquaplaning
Driving in the rain can be dangerous: poor visibility, longer braking distances – and aquaplaning. But how does aquaplaning actually occur? Why is it dangerous? And most importantly: How can aquaplaning be prevented?
What is aquaplaning?
Aquaplaning, also called hydroplaning, refers to the uncontrolled sliding of tires on a wet road surface.
When does aquaplaning occur?
Aquaplaning occurs when the tires lose contact with the ground and instead float on a film of water. On a wet road, tires need to be able to clear water from the surface to maintain grip. As soon as this is no longer possible, the water slides like a wedge between the tread and the tire.
Why is aquaplaning dangerous?
Aquaplaning is dangerous because you lose control of the vehicle and can easily cause an accident. The worst-case scenario is total aquaplaning because without direct contact with the road, your vehicle is no longer controllable, so you cannot steer or brake. But a complete loss of control of all four tires is fortunately very rare. In most cases, only part of the tires float – for example, if only the right or left tires are affected (unilateral aquaplaning). Then you can still partly control the car.
What to do if you aquaplane?
Can you feel how your car is losing its grip? These three steps will help you react correctly:
1. Reduce your speed: Remove your foot from the gas. Obviously, your speed is not commensurate with the circumstances.
2. Stay calm: Now it’s time to wait – aquaplaning usually only lasts a few seconds
3. Stay on course: Steer your car in the same way as if you weren’t aquaplaning. As soon as traction is restored, it will react as usual.
Warning: slippery road!
Take note of traffic warning sign number 114 "slippery road when wet or dirty". It warns you of stretches of road where the risk of aquaplaning is especially high.
What causes aquaplaning?
Inappropriate speed is always the main cause of aquaplaning. Other factors that favor aquaplaning are bad tires, large amounts of water and unfavorable road surface.
Aquaplaning risks in detail
- Too fast: The faster you drive, the greater the risk. However, aquaplaning isn't something that only happens over 80 km/h! You can still experience a skid at much lower speeds if the road is wet enough.
- Faulty tires: Too little tread depth, too low tire pressure and incorrect fit are risk factors for aquaplaning.
- Time of onset of rain: The first ten minutes of light rain are particularly dangerous, as the water then mixes with dust, tire abrasion and oil residues to create a slippery film.
- Significant water retention: The risk of aquaplaning is greatest in ruts, underpasses, depressions and puddles – or on roads with barely inclined or curved surfaces.
- Poor road surface: The design of the road influences how well the water drains. Modern porous asphalt absorbs a lot of water, while smooth or worn surfaces promote aquaplaning.
How can I avoid aquaplaning?
Avoid aquaplaning above all by proactive driving, adapting your speed and good tires.
More tips against aquaplaning
1. Avoid accumulated water such as ruts and large puddles if possible.
2. Keep a generous distance from the cars in front.
3. Invest in good tires. When buying, pay attention to performance on wet roads (there are also special rain tires). Narrow tires adhere better than wide ones. Observe the tire’s directional tread pattern and check tread depth and tire pressure regularly.
4. Keep your shock absorbers well maintained. Aquaplaning occurs 16 km/h earlier with worn shock absorbers than with intact ones. Rule of thumb for shock absorbers: Check after 20,000 km, replace after 80,000 km.
5. Take a safe driving course to learn how to react when it happens.
Aquaplaning and insurance
Who is liable for aquaplaning?
A properly maintained car and a driving style adapted to the weather conditions are the best insurance against aquaplaning, but accidents can happen in the blink of an eye. If other road users suffer damage as a result, you are liable for not having control of the vehicle.
Who pays for aquaplaning?
Motor vehicle liability insurance – which is mandatory in Switzerland – pays third parties for property damage and/or personal injury. If it turns out that you acted in a grossly negligent manner, the insurance company may be able to take recourse against you, i.e. reclaim some of the costs from you.
You pay for any damage to your own vehicle yourself – unless you have comprehensive accidental damage insurance, which also covers collisions. If you've injured yourself, your accident insurance will cover any treatment costs.
Frequently asked questions
At what speed does aquaplaning occur?
There is no precise speed. Aquaplaning can also occur under 80 km – depending on the amount of water, the tires and the shock absorbers.
How can I recognize aquaplaning?
You can usually feel the car aquaplane before you start to glide. Pay attention to these warning signs:
- Spray from the wheels of the car in front of you or visible standing water on the roadway
- A noise that suddenly becomes louder in the wheel well – excess water leaking underneath the vehicle (turn down the radio!)
- Noticeably easy, “loose” steering: Car has a delay in reacting to your steering movements
- Rising or fluctuating engine speed because the wheels lose grip
- ESP indicator light flickers
What tread depth should my tires have?
A minimum of 1.6 mm is required by law in Switzerland. However, for safety reasons, the TCS recommends replacing summer tires at 3 millimeters and winter tires at 4 millimeters – the deeper the tread, the better the tires displace the water and the lower the risk of aquaplaning.
Does all-wheel drive (4x4) protect against aquaplaning?
No. Once the tires float on the water film, no drive concept helps – without contact with the road, no power can be transmitted, nor can the car be steered or braked. All-wheel drive can even lead to deceptive security. Speed, tires and proactive driving remain decisive.
Do anti-lock braking systems (ABS) and Electronic Stability Program (ESP) help against aquaplaning?
Only to a limited extent. ABS and ESP only take effect when the tires are in contact with the road again. When floating, this contact is missing, so even electronic aids cannot stabilize the vehicle – they are not a substitute for an appropriate speed.
Summary: Aquaplaning doesn’t have to happen
Aquaplaning is a serious hazard on the road, but it can be effectively prevented. The key lies not in technology, but in behavior: Adapted speed, well-maintained tires and proactive driving are the best insurance against aquaplaning. If it does happen, the following applies: Stay calm, step off the gas and stay on course – the ordeal is usually over after a few seconds. If you stick to the most important rules of conduct, you’ll be a good driver, even in the rain.
Written by:
Anina Sabourdy
Anina Sabourdy is an Online Editor at AXA. She researches and writes on various insurance topics and loves the versatility of her job.
