Torque Shop: Aquaplaning or hydroplaning

Over deep puddles, even new tyres may not be able to disperse the water fast enough. ST PHOTO: KUA CHEE SIONG

I had a frightening moment a few days ago. It was raining heavily, so I slowed down to about 60kmh. At a clockwise curve along a dual-carriage way, my car drifted from the middle to the left lane. My steering felt as if it was broken as the car did not seem to respond to my inputs. Fortunately, just before the kerb railing, the car suddenly regained steering in control. Is it a steering or tyre defect? What should I do to prevent this from happening again?

What you experienced is a phenomenon known as aquaplaning or hydroplaning.

Singapore's sudden and heavy downpours fill up uneven surfaces quickly to form puddles as the water cannot drain away quickly enough. In extreme cases, these puddles are more like little ponds.

Build-up of water can also occur on well-paved surfaces, where a few millimetres of water coat the tarmac.

Over deep puddles, even new tyres may not be able to disperse the water fast enough. Worn tyres are, of course, even less able to do so.

What happens then is a build-up of water in front of the tyres, which then begin to float.

With no contact between the tyre and road surface, turning the steering wheel will have no effect on the car's direction of travel.

The situation can become more treacherous if the surface is patchy with puddles, causing severe instability as the tyres lose and then regain grip intermittently.

If you have ever seen a car wriggling or fish-tailing during heavy rain, it is because of this condition. Often, the car will eventually spin out of control.

In heavy rain, always drop your speed and look ahead for puddles. It is also important to maintain a steady speed, as sudden acceleration can also destabilise a car in such wet conditions.

Some cars come with a wet or snow drive mode, which can be useful as it dulls the throttle so as to avoid loss of traction.

Sometimes, you can gauge the situation by observing the splash created by the vehicle in front of you. If you see tracks cleared by the vehicle in front, try to stay on them.

The aquaplaning phenomenon is more likely with very wide tyres or any tyre with little tread left. Speed is, of course, a major contributing factor.

In any case, whether your car has all-wheel-drive or the range of electronic traction aids, aquaplaning can still happen.

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