When driving in rain or when the road is wet your ability to stop will be reduced. In such conditions stopping distance will increase by a factor of two. The two-second rule becomes the four-second rule.

To compensate for this reduce your speed and increase the distance between you and any vehicle in front.

Rain also acts to reduce visibility. Even with your windscreen wipers on rain can obscure the view through your windscreen. The problem is made worse when windows begin to mist over. To ease such problems:

Keep your windows clean. Clean windows are less likely to mist over.
Use a quality windscreen washer fluid.
When windows start to mist turn on your air-con or heater fan.
Replace ineffective wipers.

Dealing With Spray

Water from the sky is not the only problem. Water that is forced up from the road as vehicle drive over it can also cause hazards. This is known as spray. Spray can, in a split second, cover your windscreen and reduce visibility to almost zero.

Heavy vehicles such as trucks and buses cause the most spray but even a small family sized car travelling at a normal speed can produce enough spray to cause a hazard.

Be extra carefully after a bout of rain has ended, when your wipers are off but when there is still water on the road. If spray hit your windscreen in such circumstances then you will be effectively blinded until you have switch on your wipers and they have cleared your windscreen.

To keep spray to a minimum, create a good distance between you and any vehicle that you follow. If you see a heavy vehicle coming towards you then switch the wipers to full speed in readiness of a large quantity of water hitting your windscreen.

Aquaplaning

In heavy or persistent rain, as the rain pools on the surface of the road aquaplaning can become a serious risk. Aquaplaning is when the tyres surf the pooled water and in doing so lose contact with the road. This results in a loss of traction between tyres and road. You can tell this is happening if, when driving in the wet, your steering suddenly appears to be very light.

The way out of an aquaplane is to gently release the accelerator. This slows your car allowing the tyres to regain traction with the road.

Whilst aquaplaning never brake and avoid trying to steer. If you do you will be in danger of losing control of your car.

Water on the road is not enough to cause a car to aquaplane. If you are travelling at an appropriate speed i.e. not too fast then you are unlikely aquaplane.

Using cruise control on wet roads is not advisable as it can cause problems if you do start to aquaplane.

Roadside Puddles

These can also be hazardous. As a wheel moves through a puddle drag is caused. This drag can tug at your wheels and cause you to swerve. You will also create spray that may cover your windscreen.

Dealing With Flooding

Flooding seems to be on the increase. When confronted by a pool of water blocking your way whether you drive on through the water depends on how deep it is. If water gets into to your engine the car will stall and you will cause costly damage. It is recommended that you should never attempt to drive through water that is as high as your cars exhaust pipe.

If you do drive through a pool of water then

Drive over the highest part of the road.
Go slowly - speeding through will create a wave that will rise up towards the engine and exhaust pipe.
Use first gear and keep the revs high by slipping the clutch (keeping the clutch partly engaged). This will reduce the chances of water entering the exhaust.
Never take your foot off the accelerator, as this could allow water to enter your exhaust pipe.
Once clear of the water, dry the brakes by lightly applying them.