Heavily falling snow has many of the characteristics of fog, so if you haven’t read that section, do so now and use lights in the same way. It reduces visibility in the same way and makes bright lights scatter back in the same way, but it also seriously affects the surface you are driving on. However, if you are not used to it, fresh fallen snow can be deceptive because it feels fairly grippy, at least, until you try to stop or turn. Temperature can also affect how slippery fresh snow is. In extremely low temperatures, when the snowflakes are frozen hard, it can offer quite good grip when fresh, so a Canadian used to snow driving at minus 300 C may be taken by surprise when he drives on English snow which is more slippery at only a few degrees below freezing.
The problem is that as soon as your tyre rolls over it, the snow becomes impacted and more like ice. In a straight line this makes little difference, but when you stop or turn, the car may slide or go straight on.
If you have to get out of your car on a rural road after heavy snow, be cautious about wandering off the carriageway. Snow can hide deep ditches and holes by laying on vegetation and bridging over them or by settling on thin ice. If you fall through, it could be a fatally long time before anyone finds you because they may assume your car is abandoned.
Though four-wheel drive significantly improves the car’s traction on poor-grip surfaces, modern systems can create a false sense of security on snow and ice. This is because they have the ability to transfer the drive backwards and forwards according to how much grip the wheels have. So, when the front wheels hit a slippery patch, the torque is instantly moved to the rear until the rear wheels hit the patch. This can rob the driver of the little twitches and lightness of steering feel that warn of a slippery surface, making him think things are better than they are.
Though the 4WD can cope with this in a straight line and on gentle bends, it can’t defy the laws of physics, so when you try to stop or turn on an icy patch you have the same problems as anyone else. If the tyres can’t grip it really doesn’t matter how many wheels are driven.
That isn’t to say 4WD is unsafe or a waste of time, far from it. It gives you a greater safety margin in such conditions but you must try not to narrow that margin by driving unwisely.
Be Prepared:If snow or other danger signs are forecast think carefully about whether your journey is necessary and what route you take. If you must go out, stick to main roads as much as you can because they are always given priority for gritting and clearing and weight of traffic helps keep them clear. It also means that if you do get stuck, help shouldn’t be too far away. Certainly, avoid high altitude and exposed routes where the effects of the snowfall will be worse. Never ignore signs saying routes are blocked, even if you are in a 4×4, not least because if you do get stuck, nobody is going to expect you to be there.
It is vital you take clothing suitable for cold weather, including boots in case you need to get out. High-energy food and a hot drink are also wise. Take a shovel and invest in a folding one you can keep in the boot if you regularly need to travel in snow. Something to put under the wheels to give grip may also be useful in freezing conditions: sacking or pieces of carpet are fine.
Finally, let someone know your intended route and your estimate of the time you will arrive, so if you do not turn up they know to call the emergency services.
If you think nobody would be stupid enough to venture out in heavy snow without preparations, think again. In the worst snowfalls southern England had seen for many years, Kent police were amazed by the stupidity of a man whose car had broken down on a barely passable motorway. In spite of the obviously bad weather, and warnings not to travel being broadcast on national and local radio, he had set out to play squash with only the clothes he was wearing, namely the shorts and tee-shirt he intended to play in. When they found him he was so cold he could hardly speak.