Aquaplaning can be a terrifying experience, and as it has been said before, it is not the initial stages of an incident that will cause loss of control, it will be what the driver of the vehicle does in response to it that incident that will become the problem.

To explain what aquaplaning is all about we need to go off on a bit of a tangent for a moment, but don’t worry, as there is some significance in what follows.

If you were to go out onto a freshly formed soft snowdrift, and stand on the top of it on a large board, you would be quite stable, even to the point that you could jump up and down on it.  If you stepped off your board you would sink up to your crotch in snow, simply because it was the board that was keeping you on the surface.  On top of the snowdrift your board was spreading your body weight over a large surface area and so preventing you from sinking, whereas your shoes, which have a much smaller surface area, would allow you to sink into the snow.  Applying this to your car, if you have a model that has nice wide and sporty tyres, these will provide you with lots of nice grip for cornering on a dry road, but then work completely against you in the wet, simply because the wide tyres spread the weight of your car over such a larger surface area of road by comparison with narrower tyres.

Cars get their grip through their tyres through friction, which is created by down force, which in the case of a road car, this comes from its actual overall weight.  If the tyre has a wide footprint, then the actual down force per block of tread will be less than the same car on narrow tyres, but because the wide tyres have more area in contact with the road then the two factors (weight and contact area) cancel each other out.

Aquaplaning is a condition whereby the tyres of a car lose contact with the road surface through riding on a layer of water, in much the same way as a surf board will skim over the surface of a wave, but why does the car aquaplane?  The simple and only answer to that is that tyres have grooves and channels within the tread area that are designed to disperse water so that the blocks of tread can remain in contact with the road surface in wet conditions.  When it is being driven too fast for the conditions the tyres are unable to disperse the surface water quickly enough and so will begin to skim over the surface, and this will first happen to the front tyres.  The back end is far less likely to aquaplane because the tyres at the rear have to disperse less water than the front.  This is because the rear tyres are running in line with the front ones, and as the front tyres are cutting a swathe through the surface water on the road they are more or less leaving a channel of clear tarmac for the rear tyres to run in, making aquaplaning at the back very unlikely.  If the rear did aquaplane it will be long after the front end had lost out and by that time it wouldn’t matter a jot whether the rear of the car was gripping the road or not.

All too often, when a car aquaplanes, it will go into a spin and leave the carriageway because when this happens all grip is lost and the direction of travel is then in the hands of the laws of physics and the actions of the driver.  The reason the car goes into a spin is because of two things, either applied together or individually, and both of which are induced by the driver, he or she being the bit that causes the loss of control.  The first thing that happens is that as soon as the driver becomes alarmed at the behaviour of the car he/she will snap their foot off the gas, which changes the weight distribution within the car, effectively upsetting the balance. The next response is to instinctively move the steering wheel, which now takes the car off line and disturbs the balance even more. This will usually then be followed by an application of the brakes, and by now it is all going horribly wrong.

The best course of action to take in order to deal with aquaplaning is this.  As soon as you feel the car begin to aquaplane just freeze everything as you are, as in lock your foot solid in a neutral throttle zone, this being a state where the engine is neither accelerating or decelerating the car, and keep the steering locked at a straight ahead position until you get through the bit of water the has caused you concern, because changing the balance of the car at the point of aquaplaning will provoke something to happen rather than cure it.  If by chance you have induced the car to go out of line, bang the clutch pedal down (no brake) to neutralise the car and make very gentle steering movements to counter the involuntary movement of the car.  If there is any braking done at any time it will only make everything worse, so do not make any speed changes in any way, shape or form.

The period of aquaplaning, for 99% of occasions, will be for no more than a second or two.  By going rigid you can ride it out, and then reduce speed once the moment is over and your tyres are back in contact with the road.  If you have gone into a complete spin then you have gone beyond the point of return and then you are best just to tread heavily on the brake and brace yourself, because unless you have the experience or the extraordinary skills to do so you will not intentionally pull out of it.

As said before, it is not the initial stages of an incident that will cause loss of control of the vehicle, it will be what the driver does in response the incident that will become the problem.  That being said, the general rule is that in an emergency such as this, the first thing to do is don’t.


Julian Smith

Ride Drive Limited