Driving in the snow is not something to take lightly. Beyond our skill under optimal conditions, snow demands a much higher level of attention, because in addition to not cooperating, it can also hide very negative aspects of the road. So why does the car feel like it's sliding on soap? It all comes down to a combination of G-forces, grip, and the influence of snow on that latter property. Once you absorb that data, driving in the snow becomes a safer experience.
Judging by the comments from my contacts, the northern hemisphere is going through a Frostpunk-style cold season, while the southern hemisphere is wrapped in flames. Leaving aside any claims about climate change, the point is that we must keep living and working like any other day, only adapting to the hostility of the weather. That means many people out there are forced to drive in the snow, a practice that I personally would try to avoid. Why is there such a big change even between wet ground and snowy terrain? The best way to answer that is by studying the physics of driving in the snow, and the video from the Engineering Explained channel does an excellent job:
How to Drive in the Snow
G-forces and grip. When you are in your stopped car, the Earth's gravity pulls downward, equivalent to 1G. On roller coasters and similar attractions, G-forces are more intense, to the point that several people have been removed from them completely fainted. Now, your car's tires cannot escape physics, and on dry ground they withstand up to 1G in all directions before sliding. The video helps us visualize a traction circle that defines the influence of 1G. When the ground is wet, that circle becomes smaller, and the limit becomes 0.7G. This is even worse in snow, and with just 0.3G the car will lose control. Finally, the most adverse scenario is ice. Any aspiration to stable driving disappears with 0.15G. Accelerating, braking, turning a corner, it doesn't matter. If you exceed that traction circle, you'll be in trouble.
Another way to visualize it is through the required braking distance if you are moving at 48-50 kilometers per hour:
- On dry ground, you'll need about 9 meters to brake completely.
- If the asphalt is wet, the distance rises to 13 meters.
- On snow the jump is impressive, reaching 30 meters.
- Ice essentially doubles snow with 60 meters.
However, all these calculations get worse with speed. Why? Because braking distance is a function of speed squared, so the distance is multiplied by four:
- At a speed of 100 kilometers per hour, 36 meters is recommended on dry ground.
- For wet ground, the distance extends to 52 meters.
- Snow reveals all its associated risk with 120-121 meters.
- 244 meters for ice.
When turning a corner, it is very important to consider the radius of the curve. Imagine a radius of 9 meters: With dry asphalt, the maximum speed is about 33 kilometers per hour. Wet ground forces us to slow down to 29 km/h. With snow, the maximum is 19 km/h, and when driving on ice, we should not exceed 12-13 km/h.
With all that theory on the table, the recommendations on how to drive in the snow more safely are reduced to four points:
- Optimize the traction circle. This is achieved by installing winter tires, specially prepared to travel in cold environments, with ice and snow. Now, using these tires does not mean the driver can relax in the snow. Quite the contrary: all they do is improve the safety margin. Nobody is more skilled for having winter tires, and G-forces are not going anywhere.
- Driving should not only be slower, but also smooth. Any quick and/or hard action on the steering wheel, accelerator, or brakes harms the vehicle's stability, losing traction in the process. The overall reduction in speed is inevitable due to weather conditions, but it's worth remembering.
- Increase the time and distance that separates you from a vehicle ahead. Expect the best, prepare for the worst, and don't forget the surprise factor. Under normal conditions, 3 or 4 seconds are usually the average, but when driving in snow or ice, you should think about 8 seconds or more. That will give you a margin wide enough to respond appropriately.
- If the snow is very deep, keep the car moving. Of course, you have to brake when necessary, but the last thing you want is to end up trapped and abuse the accelerator trying to get out. If you see a red light in the distance, it's preferable to reduce speed more to give time for the change and keep moving.
As always, the ideal solution is not to drive in the snow, but if you have no alternative, we hope this helps you.
