As shown. If the car brakes when turning or turns while braking, it will also produce side-slip friction to enable the car to turn, as shown in Figure 2-1 (b). The ground braking force determines the length of the braking distance, and the sliding friction determines the directional stability of the car during braking. Here, the side sliding friction force acting on the front wheel is called a turning force, and the side sliding friction force acting on the rear wheel is called a lateral force. The turning force is related to the directional maneuverability of the car, which ensures that the car can turn according to the wishes of the driver; the lateral force is related to the directional stability of the car, which ensures the direction of travel of the car. The greater the turning force, the better the directional maneuverability of the car; the greater the lateral force, the better the directional stability of the car.As mentioned above, applying proper braking can effectively stop the car. Excessive braking intensity is the main cause of various dangerous sports in the car. Therefore, when the car is driving, it is necessary to perform braking operations according to the road conditions such as ice road, snow road, gravel road, bad road, wet road, dry road, straight road, curved road, etc. Care must be taken from time to time not to completely lock the wheels.