Cause of skidding: grip on slippery roads is very small. The braking forces must not exceed the adhesion forces. Even a slight pressure on the brake pedal on a slippery road leads to blocking of the wheels and skidding of the car.
Cause of skidding: blocking of all four wheels at the same time does not occur due to different response times of each working brake cylinder, the state of the brake system, the condition of the tires, sudden gas supply, sharp rotation of the steering wheel, different grip on the road of the left and right wheels of the car. For example, on one axle, the left wheel is blocked, does not rotate, and the right wheel, due to the above reasons, continues to rotate, and the car rotates around the blocked wheel. Studies have shown that the difference between the braking torques of the right and left wheels reaches 25-30%. This is enough to make the car start to turn. And if there is any obstacle in the way of the wheel moving in a circle (frozen stone, stick, frozen track or even just a piece of ice), the vehicle may roll over.
First of all, you need to learn how to drive a car when sliding in a straight direction - skidding. To do this, you must go to a free area 50x200 m with a slippery surface, preferably with a smooth asphalt concrete surface, watered. When driving in a straight line, brake sharply by applying emergency braking. In this case, the wheels will not rotate, as they say, they will be blocked, and the car will move forward several meters. After that, get out of the car and inspect the track left by the car when braking. You will see a dry track on the surface of the road, resulting from the slip of the wheels. The length of these strips depends on the type of road surface, the effectiveness of the brakes and the condition of the tire tread.
After that, repeat the maneuver, with «flair», inherent in a good driver so that the wheels do not block. Continue training until you are sure that there are no stripes on the wet road behind the car.
This workout should be done immediately after practicing the various dry braking techniques we covered earlier. As you now do this exercise, you will determine which of these four methods of braking on slippery roads is the most effective.
Further on this site, you learn to perform turns on a slippery surface. Braking the car sharply and hard on a curve ensures that the locked wheels stop guiding the car around the curve and move straight ahead. You practically choose such a trajectory of movement and a method of braking so that the car's movement remains controlled.
When performing these exercises, you must make sure that the length of the skidding zone of the car depends not only on the value of the coefficient of adhesion of the tires to the road, but also on the value of the speed you develop. At a high speed of movement, the length of direct sliding - skidding can be more than 100 m.
So remember: the lower the speed, the lower the user!
Next, we should practically study the side slip, which is primarily subjected to the rear wheels of the car; drivers call this slipping a skid.
When braking, the center of gravity of the car is transferred forward, and the sharper the braking, the greater the load on the front wheels, and less on the rear.
The traction of the rear wheels of the car is less. Consequently, the probability of blocking the rear wheels is greater and the rear axle skids more often.
Remember the four basic rules for skidding.
- 1. Never slow down. This will not help, but will only aggravate the skid. An unknown force and a desire to stop are irresistibly pulling your foot to the brake. Do not do that.
- 2. Do not press the clutch pedal. It practically does nothing for you.
- 3. Do not release the gas pedal abruptly. This braking and exacerbates the skid. But if you smoothly slightly increase the gas, you can reduce the skid. If the skid is severe, fully release the gas pedal.
- 4. Turn the steering wheel in the direction of the skid. If the vehicle skids to the left, turn the steering wheel to the left. If the rear end slid to the right, turn the steering wheel in the same direction. This must be brought to automatism, performed without jerks, but quickly. Hands turn the steering wheel on the side sector. Moreover, the rotation of the wheels should be carried out the stronger, the greater the skid of the car. This is the only way to control the car in a side skid.
Front wheel drive features «tenth» during the elimination of a skid and when cornering on a slippery road:
- tractive effort falls on the front wheels and when driving on a straight road, this car is much less likely to skid;
- the hatchback is less prone to skidding than the sedan, and even more so the station wagon. If the rear axle still slips, then the duration of the skid and its amplitude will also be less;
- loss of traction of the wheels with the road occurs when cornering;
- slow down before the turn;
- when cornering, move at a constant speed or with a slight acceleration;
- if the rear wheels have lost traction, increase the fuel supply, this is enough to stabilize the car;
- do not sharply, carefully turn the steering wheel in the direction of skidding;
- at high speed or with a sharp increase in gas supply on a turn, the front drive wheels may lose traction, and the car will begin to drift, in this case, do not turn the steering wheel, the wheels are not steerable; reduce the fuel supply. This will restore the grip of the drive wheels with the road, and the car will become controllable.
Then move on to training the car out of the skid, operating the controls, as shown in Fig. 12.
Please note: the front wheels must always «look» strictly in the direction of travel. This is what you should strive for. An extra turn of the steering wheel in a panic may not stabilize the rotation, but further increase the deflection of the rear of the car. Therefore, turn the steering wheel quickly, but at a certain angle. During training, you should feel it. It is necessary to start turning the steering wheel in the other direction a little earlier than the skidding of the rear of the car stops. At the same time, try to keep the engine speed in such a way that the drive wheels roll without slipping.
When driving on slippery roads:
- it is better to prevent a skid than to try to get out of it; consider road conditions and leave time for reaction; move the steering wheel from side to side at a frequency of up to 2 times per second. This will allow you to be in a state of constant readiness for action to eliminate the skid;
- no theory can replace practice. Learn how to drive safely on slippery surfaces. Even one or two lessons with an experienced instructor will allow you to feel confident on the road in any situation.
The rapid and complete elimination of skidding depends on your experience, ability and ability to take your will into a fist. By practicing this maneuver, you will be able not only to master the skid, but also to accurately determine whether a skid can occur on a given road and in given conditions. You will learn to adapt the speed of your car to the traffic conditions, especially when cornering.