EXPLAINER: Why is freezing fog worse for drivers than normal fog and what can we do to stay safe?

With freezing fog and ice leading to very dangerous driving conditions, the Road Safety Authority (RSA) has issued advice for driving in freezing fog.

The current freezing fog combined with icy conditions makes for a particularly treacherous combination.

CEO of the RSA Noel Brett said: “Dense fog reduces visibility greatly and makes driving very dangerous. However freezing fog, when liquid fog droplets freeze to surfaces, can make it difficult to keep the windscreen surface clear.

"Combined with icy road surfaces – it’s a driver's worst nightmare."

As visibility is reduced in such conditions a collision involving one vehicle can quickly involve many others, especially if driving too fast and too close to one another. The greatest risk is of a multiple-vehicle pile-up on roads with higher speeds such as motorways and dual carriageways.

So what can drivers do to reduce the risk of being involved in a potentially devastating collision?

“Road users should follow weather forecasts and general advice about driving conditions, and should avoid driving, cycling or walking in fog unless absolutely necessary," said Mr Brett.

“If you must drive in fog, allow plenty of extra time for your journey.

"Before setting out, check that your car is in good working order, particularly that all the lights, including fog lights, work properly and are clean.

“Reduce your speed and keep your distance from the vehicle in front. You should always be able to stop in the distance you can see in front of you. If the fog closes in, reduce your speed.”

Other tips for road users include:

• Switch on headlights and fog lamps if visibility is reduced
• As you enter fog, check your mirrors and slow down. Use your foot brake lightly so that your lights warn following drivers.
• Do not drive on the tail-lights of the vehicle in front (Target Fixing). This can give a false sense of security and you will be too close to be able to brake safely.
• Switch off distracting noise and open the window slightly so that you can listen for other traffic, especially at crossroads and junctions
• Beware of other drivers who are not using their headlights.
• Beware of speeding up as soon as visibility improves slightly. In patchy fog you could find yourself “driving blind” again only moments later.
• Carry a mobile phone, high visibility jacket and torch in the event of a breakdown or collision. In the event of a breakdown park the vehicle well in off the road, get out and stand well back from the side of the road. Phone the emergency services and do not attempt to stand or walk on the road.
• Remember to switch off your fog lights when visibility improves.