Flash flooding advice for drivers

Motorists are being warned that the inevitable flash floods that come with heavy rain make driving conditions particularly hazardous, with poor visibility, difficult car control, slippery road surfaces and increased stopping distances.

“A suddenly very wet road surface increases the chances of slipping when braking or steering, which is a problem not just for motorists but cyclists and motorcyclists too,” said Peter Rodger, IAM’s chief examiner.

If your journey is unavoidable, and you have to drive through deep water, the IAM recommends taking the following precautions:

• Drive on the highest section of the road and don't set off if a vehicle is approaching you.
• Leave time and space to avoid swamping other cars and pedestrians.
• Drive slowly and keep going once you have started – make sure you have a clear run. In a manual car, keep the revs high by slipping the clutch (which means the clutch is not fully engaged) all the time you are in the water.
• If you can’t see where you are going to come out of the water, think twice about starting to drive into it.
• Under no circumstances in deep water take your foot off the accelerator, as this could allow water to travel up the exhaust pipe.
• Once you're out of the water, dry the brakes before you need them. The best way is to lightly apply them for a few seconds as you drive along, after checking nothing is following you too closely.

“Another thing to consider when driving in wet conditions is stopping distances,” Roger said. “Drop your speed and give yourself more time to slow down. Visibility will be lower during heavy rain, so make a point of turning on your headlights whenever you need to use your windscreen wipers. Use your air conditioning to help clear the windows.”