Summary of subject four knowledge points

Recently, I often see people posting to ask what to test in subject four, which is actually to test some safe and civilized driving problems. So now, combined with my personal experience, I will give some knowledge points to those students who are ready to take subject 4 or fail to take subject 4.

1. Influence of weather conditions on safe driving

(1) In rainy days, the main factors that directly affect safety are the slippery road surface and the obstruction of sight. When the vehicle runs on the slippery road, the adhesion of the road surface drops sharply with the increase of the vehicle speed. When braking, the vehicle is prone to sideslip or sideslip.

(2) In foggy days, due to low visibility and blurred vision, drivers can't see clearly the obstacles ahead, so they must drive at a low speed to avoid traffic accidents. When the vehicle is driving at a low speed, the driving resistance will not be affected, and the side slip will not occur if the brake is too fast.

(3) In windy weather, due to the constant change of wind speed and direction, when the vehicle is driving at high speed, the steering wheel will suddenly feel "taken away" due to the influence of crosswind, and a strong wind will strike, which may lead to the lateral deviation of the vehicle during driving. Therefore, when driving in windy weather, drivers should hold the steering wheel tightly and slow down.

2. The influence of pedestrians on safe driving

There are different pedestrians on the road, which can be divided into old people, young people and children. The characteristics of all kinds of pedestrians are different, and the traffic experience of the same kind of pedestrians is also different. The main feature of pedestrians is that they walk at will and their directions are changeable.

Influence of overtaking in violation of regulations on safe driving

When the other vehicle suddenly overtakes and occupies its own lane, you should try to slow down and avoid it, and try to speed up or keep chasing the other party in anger to force it out of the way, rather than forcibly blocking its way.

3. The influence of road conditions on safe driving

(1) The visibility of road environment is low at night, which is not conducive to observing road traffic conditions. When driving at night, the driver's gaze on the object is obviously worse than during the day, and the sight distance becomes shorter, which affects the observation. At the same time, he is highly concentrated and easily tired. When driving, you can't see the road ahead clearly in a short time after being illuminated by the opposite light. When driving at night, when the lights of the whole car suddenly go out, you should immediately brake, pull over, stop driving, stop at the same place, and don't brake suddenly.

(2) Snow and ice pavement, the pavement is slippery, and the sunlight reflection is strong, which affects the line of sight, because the reflection of snow on light is easy to cause the driver to be dazzled and have an illusion. When driving on the ice and snow road, the stability of the vehicle decreases and the braking distance is extended. When the acceleration is too fast, the wheels are prone to idling or slipping.

(3) The muddy road surface is particularly soft and sticky, and the driving resistance of vehicles is large, the adhesion is reduced, the wheels are easy to slip, and the vehicles are easy to slip or flick their tails when braking, leading to traffic accidents.

(4) Because the road surface is covered with water, the financial and trade law can clearly see the underwater road surface. After confirming safety, shift to low gear and pass slowly. When the road surface is damaged by water, you can't take risks, because you can't see hidden pits and raised roads.

(5) Most roads in mountainous areas are built by mountains and cliffs, with long and steep slopes, narrow roads and many dangerous sections.

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