Heavy rainfall can make driving more dangerous and surface water on the roads can cause your car to aquaplane, which may result in you losing control of your vehicle.
Unfortunately, in the UK, we’re used to wet weather – according to the Met Office, some of the wettest parts of the UK receive over 4 metres of rainfall in a year.
This means we'll likely have to drive in heavy rain at some point, so it's important to know about aquaplaning and how to avoid it.
In this article
What is aquaplaning (or hydroplaning)?
Aquaplaning is when water builds up in front of your tyres faster than the weight of your vehicle can displace it. This forces water below the tyre, creating a layer of water between your tyre and the road.
Because of this, your tyres lose their grip on the road. With no traction, you could lose control of the car temporarily, and be unable to steer, brake or accelerate.
Motorbikes are also vulnerable to aquaplaning – it can actually be a lot more dangerous for motorcyclists as losing control could result in the bike falling over.
Aquaplaning is also known as hydroplaning.
Learn more about driving in heavy rain and floods.
How do you know your car is aquaplaning?
If your vehicle is aquaplaning, you might notice:
- The steering suddenly going 'light'.
- The engine suddenly getting louder.
- The back of your vehicle drifting to the side.
What causes aquaplaning?
For a vehicle to aquaplane there needs to be standing water, such as puddles, on the roads. If it’s been raining for a few minutes, there's a chance of standing water and therefore a risk of aquaplaning.
Once there's standing water, the risk of aquaplaning is mostly affected by 3 factors:
The deeper the water is, the harder it’ll be for your tyres to keep a steady grip.
Standing water and puddles can often be deeper than you might think, so always drive with caution.
Aquaplaning is most likely to occur at higher speeds, and sudden accelerations could cause your car to aquaplane.
It's always important to lower your speed when it's raining heavily, especially if there’s enough rain to form puddles or standing water.
Worn tyres with low tread depth won't clear water from the road as effectively as newer tyres.
So if your tyres are worn and have low tread depth, your chances of aquaplaning increase. It’s important to check your tyres regularly, to make sure they are fit for the roads.
Wide low profile tyres have an increased chance of aquaplaning.
While this isn’t something people can change, those who drive cars with wide tyres need to be especially conscious during wet weather. The pressure and condition of the tyres for these cars is even more important.
What should I do if my car starts aquaplaning?
If your vehicle begins to aquaplane, you should:
- Avoid slamming the brakes. It might be your first instinct to stop the car, but you could end up causing your car to lose control and spin.
- Slowly and gently ease off the accelerator, making sure you hold the steering wheel straight and steady.
- Relax your grip on the steering wheel but maintain control until the positive feeling of contact with the road surface returns.
- When you feel yourself gaining more control of the car, brake to bring your speed down.
How to react to aquaplaning
If you notice your car start to aquaplane, the most important thing to remember is to try and stay calm.
While it can be difficult, try to avoid panicking and doing something severe – like slamming the brakes or swerving – as you may cause the vehicle to skid and possibly cause a collision.
Follow the advice above and hopefully you’ll quickly feel yourself gain more control of the vehicle.
How to avoid aquaplaning
Aquaplaning can be a distressing experience so it’s best to do what you can to stop it from happening in the first place.
1. Plan your journey ahead of time
Keep your eye on warnings for severe weather conditions. If heavy rain is forecast or you know certain roads have lots of standing water, you might want to consider rescheduling or delaying your journey if possible.
2. Drive smoothly
Try to avoid harsh braking and hard cornering as this can increase the risk of aquaplaning and losing control of the vehicle.
3. Check your tyres regularly
Make sure your tyres are inflated properly. You should also consider changing tyres before they reach the legal minimum tyre tread of 1.6mm, especially if you're driving in winter when roads are more likely to be wet.
While the legal limit is 1.6mm, any tyre with much less than 3mm of tread results in a considerably higher chance of aquaplaning.
4. Be aware of where to drive on the road
Puddles tend to form at the side of the road, along the pavement. If it’s been raining or there's standing water across the road then it'll often be shallower towards the centre-line.
5. Avoid driving in any ruts in the road
Ruts are often caused by heavy goods vehicles and can be full of water even if the rain has stopped. Keep an eye out for these and try to avoid driving through them.
6. Remember your stopping distances
It’s always important to leave enough distance between you and the vehicle in front, but this is particularly crucial during wet weather. Being forced to brake suddenly or swerve due to the car in front slowing or stopping could result in your vehicle aquaplaning.
Even without standing water and no risk of aquaplaning, stopping distances in wet weather will always be much longer, simply because your tyres have less grip. Keep at least twice the stopping distance you would in dry conditions.
7. Don’t use cruise control
While cruise control can be useful at times, you shouldn't use it when the weather is bad. This is because it might cause you to get too close to other vehicles and increase the chance of collisions.
Cruise control can also cause uncontrolled wheelspin in an aquaplaning situation, making it especially dangerous. It should be switched off if there's any likelihood of standing water on the roads
Improved vehicle technology and aquaplaning
Vehicle and tyre technology is always developing and improving, meaning modern vehicles are generally better equipped to tackle wet conditions.
The rise in all-wheel drive systems mean several modern cars have better grip on the roads in icy or slippery conditions.
As vehicle and tyre technology continues to improve, hopefully in the future it will be much easier to avoid and manage aquaplaning.
At present, though, aquaplaning remains a risk during heavy bouts of rain, so make sure to follow the advice above in order to drive safely.
Published: 4 June 2019 | Updated:3 May 2022 | Author: The AA