If you have to drive in these conditions, then here are some tips to help you to complete your journey safely.

Fog can be one of the most dangerous weather conditions to drive in, and should be avoided if possible. Minor accidents can quickly escalate as other drivers can not anticipate difficulties ahead, and often drive too close to each other for the conditions. Pile-ups and more serious injury or loss of life can be so easily be prevented if advice is followed.

• In thick fog, if you can see the rear lights of the car ahead, then you are too close to stop in an emergency.

• If at all possible, it is wise to arrange alternative transport or delay your journey until conditions improve.

• If you have to drive, allow extra time for your journey and prepare. Check that all your lights are working, and clean your windscreen before setting out.

• SLOW DOWN - check your speedometer occasionally as it is more difficult to judge your speed from external events.

• be able to stop well within the distance that you can see clear ahead.

• remember that the road surface may be more slippery in fog, so make sure you allow for this when braking.

• use your wipers to keep the windscreen clear.

• use your demister and heated windscreen to keep the inside of the screen clear.

• avoid the temptation to speed up when the road clears between patches of fog.

• turn off your radio/cd and open your window enough to hear approaching traffic.

Use of lights in fog.

• In daylight - use dipped headlights and/or front fog lights at times of reduced visibility. If fitted, fog lights are preferable, but either type of light will avoid dazzling other drivers or pedestrians, whilst being visible from a greater distance that side lights.

• At dusk - use dipped beams, and at other times of poor visibility.

• At night - in thicker areas of fog use fog lights, alternating to dipped lights in stretches of thin fog.

• By law fog lights must be switched off when visibility improves, as they are designed to reduce dazzle in foggy conditions alone.

• High-intensity rear fog lights should only be used when visibility is seriously reduced, for example when you can not see for more than 100 meters (328 feet) ahead.

Driving in Traffic.

• Slow down in fog leaving plenty of stopping distance. Fog makes it difficult, or impossible, to anticipate circumstances that are ahead, so allow yourself extra time to respond by slowing down, and keeping your distance from vehicle ahead. 'Hanging on' to the lights of the vehicle in front will give you a false impression of the fog density as the lights displace some of the fog.

• Watch out for emergency vehicles.

• Take particular care at junctions, especially when turning right. Indicate as early as possible, open your window to listen for approaching traffic, and only turn when you know it is safe to do so. Make as much use of your lights as you can in this situation by keeping your foot on the brake to give extra warning to other drivers that you have stopped. Use your horn if it will help the situation.

• Overtaking should be avoided as visibility can alter and you may not be able to see oncoming traffic.

• Road markings may be difficult to recognise in fog. Your dipped headlights will be able to pick up reflective studs. Try to position yourself centrally between the lane lines or studs. It is EXTREMELY DANGEROUS to drive on the centre line as a means of navigation in fog.

• Avoid parking on a road in fog if possible. Off street parking would be preferable.

• In the case of break down you should try to get your vehicle off the road if possible. If you are causing an obstruction, inform the police and arrange for removal as soon as possible. Never leave the vehicle without warning lights or on the wrong side of the road.