I don't see why you have a problem with driving in snow. It's kind of fun.

Let us get more specific

The points the above noders make are all correct, but ignore the difference between black ice, a thick layer of ice, snow, snow on ice, slush on ice and refrozen slush. (See Finnish words for snow; For the record, musta jää, kaljama, lumi, polanteet, sohjoa jäällä and röpelö respectively.) Each of them has completely different properties. The first snow of the winter - a thin layer of fresh, powder snow - affects the traction only a little. Ice, packed or untouched layers of snow and slush are the real danger, because they prevent the wheels from touching the asphalt.

First of all, the greatest danger is not crashing to the ditch or into a tree. That's what modern, safe cars can handle. The real danger is drifting to a lane going to the opposite direction, where the relative speed of impact is twice the speed of impact to a stationary tree, according to the Galilean transformation. No safety device can help if a 60-ton truck flattens your tiny tin can of a Sierra.

Types of ice and snow

In My Holy Opinion, thick layers of ice are the most dangerous. Lack of traction is not the greatest danger in them. They occur in the spring, when the snow melts in the day and refreezes in the night, compacting to hard, transluscent forms. They are hard, irregular in form and 2-10 cm thick. That's why they're dangerous. You can't crush them and drive over them: suddenly the road drives the car, not you! This scares the shit out of an inexperienced driver. To drive on a road with thick layers of ice, just drive where everyone else has driven. Blocks of refrozen slush form where no one drives. A lot of accidents happen when someone is trying to pass a car and hits this ice block between the lanes.

Then you have slush or freshly fallen snow on ice or compacted snow. Assume no traction. Braking distances are ridiculously long. You can get even 200 m from a highway speed of 100-120 km/h. The braking distance for big cars with a speed of 100 km/h will start to resemble the distances which trains need for a complete halt. Simply stop at each intersection where you have any doubts about visibility. If you're speeding through the intersection and another car comes doing the same, you can do nothing. Combine this with a dirt road and blocks of ice: crashing is 100% guaranteed, if you do not slow the car into a complete halt, until you know you're safe to go. A good '86 Toyota Camry was wasted by my mother because of this. I would've wanted it!

Ice on the road isn't that difficult, but I've witnessed an accident on the first day of season with icy roads. After I saw it, I tried driving in equivalent conditions in a parking lot with a 180 degree turn. The conclusion is that in a city, you can go almost any curve with 30 km/h, but you have to consider the steepness of the curve at 35 km/h, and 40 km/h is too much. Yes, it is this precise: only 5 km/h make the difference.

Snow is relatively easy to drive in. A compacted layer of snow has quite good a traction for turning. Untouched, fresh snow can be somewhat annoying, because you have to compact it as you go. Obviously the layer isn't perfectly even, so the wheels jerk into random directions. You have to correct these movements continuosly. Anything that's under the layer of snow is concealed from you. You cannot know in advance if there are forms of snow, ice or frozen slush hiding under the white blanket of newfallen snow. The road may drive the car. The speed limit is 35 km/h for a 90-180 degree street crossing as mentioned earlier. Drive slower in the turn, about 25-30 km/h, if the compacted layer is icy.

Black ice is said to be the most dangerous, because it's supposedly unpredictable. This is where Celsius degrees come handy. If the road is wet, subzero means black ice. Black ice shines in the headlights unlike water, which absorbs nearly all the light and only glimmers faintly. You can slow down and maintain a longer distance to the next car. Usually the road is covered in black ice only partially. So, if you lose traction, you have good chances of regaining it quickly. Then the car goes wherever the steering wheels are pointing at. If you have panicked and jerked the wheel, the result is exactly the same if the road was dry: the steering wheels are going sideways, and the car flips over.

Refrozen slush in a frost means that the traction is quite good. The car has to break the protruding forms of ice, which generates traction. Other cars will grind the ice into small pieces, so that it's like driving in a gravel road.

Technical considerations on the car

The car makes a big difference when driving in snowy weather. The more weight there is on the tyre, the more traction it gives. Hence the safest car has its center of gravity near the centerpoint of the car, so that the weight and the traction is spread evenly over the wheels. The car I have been driving, a '92 Volvo has its center of gravity in the front, so that the wheels in the back lose their traction easily. That makes the car dangerous, because it will start spinning in a curve. The front goes in the direction of the curve, the back goes to the forest. This can be corrected letting the car get a grip on the road first, then using the accelerator.

I haven't driven a car with the center of gravity in the back, but I think it will be even worse. The tyre has the most traction when it's going forward, i.e. not turning. The consequence is that when the steering wheels turn, the lose the traction even more easily that the back wheels. The car goes exactly to the same direction where it was going before losing the traction, according to the Newton's First Law of Motion. The driver becomes a passanger.

Front wheel drive means that if traction is lost, the car will go forward and cannot be controlled until the front wheels regain traction. They have the least of safety. You need some skill to drive a back wheel drive car in snow, but it's safer. In a curve, you can step down the accelerator, so that the back wheels will grind deeper into the snow and get a better grip. Rally drivers do this all the time, and it looks cool. Not to be done by women* or other timid persons. Four wheel drive needs even more skill, as you already noted. It stays on the road better, but when it starts to slide, it's harder to control. The safest is an "intelligent four wheel drive". It is normally a front wheel drive, but when it detects loss of traction in the front, it will connect the back wheels to the engine. This type can be too safe. When the car corrects the loss of traction because you speed to a curve, you easily forget the danger.

ABS is not the solution to all wheel-locking problems. It will make braking easier, but not idiot-proof. Any kind of braking -- including ABS braking -- can make the wheels to lose the remains of the traction it might have had. ABS braking is also braking, after all. Pumping the brake applies also to ABS. Keep the pedal down for one second, release for two, brake for a second again etc. In a non-ABS car, this prevents a total loss of control, but in an ABS car you may be able to drive through the curve without any incident.


Whatever you read, Siberia will teach.

Special Thanks and Olympics for: CentrX, Catchpole

* the women I know tend to be preoccupied with this "getting from point A to point B" thing.