The influence of bad weather conditions on safe driving is

Influence of bad weather on safe driving of vehicles

Bad weather, also known as disastrous weather, often has an extremely adverse impact on the safe operation of vehicles, and sometimes even leads to road traffic accidents. How to ensure the safe driving of vehicles in disastrous weather has become a very popular research direction. This paper analyzes the influences of four common disastrous weather on road traffic safety, such as human wind, rain and snow, human fog and high temperature, and puts forward corresponding methods and measures, with a view to reduce the adverse effects of disastrous weather on road traffic and improve road traffic safety.

The warning signals of disastrous weather are mainly divided into eleven categories, such as typhoon, rainstorm, high temperature, cold wave, human fog, thunderstorm and gale, human wind, sandstorm, hail, blizzard and road icing. These disastrous weather will have a negative impact on the normal operation of vehicles on the road and even lead to traffic safety accidents. This paper mainly analyzes the influence of strong wind, rain and snow, human fog and high temperature on road traffic.

(A) the impact of strong winds on road traffic

In the case of straight road lines and good road conditions, vehicles usually travel at a faster speed. At this time, if there is wind, the vehicle will swing. The reason is that the force of the wind on the vehicle is uneven and the direction of action is irregular, and then

In addition, there are various clearance spaces in the structure of the vehicle itself, and the fast-flowing air forms friction resistance of different sizes in the irregular car body. When the speed reaches a certain level, the vehicle will swing. If the wind is strong, it will make traffic

Deviation from the driving route, and this deviation is aggravated with the increase of vehicle speed. According to the calculation, when an ordinary car is driving at the speed of 100km /h, if it encounters a crosswind with the wind speed of 100m /s, the vehicle will deviate from the center line by 4~5 meters within the journey of 100 m, and the deviation of the bus will be even worse. When the weather is clear and the visibility is high, the human wind can easily cause the driver's negligence. If the driver does not control properly at this time, it is easy to cause an accident. In addition to affecting the safety of the vehicle itself, human wind will cause falling objects, such as blown branches and telephone poles, which will affect the driving safety of the vehicle. In northern China, human wind may also cause sand fog, which will suddenly reduce visibility and easily lead to traffic accidents.

(b) the impact of rain and snow on road traffic

For rainy and snowy weather, the prominent problem is the decrease of road friction coefficient, which leads to road traffic accidents. On the slippery road surface, it is easy to form a thin water film, which separates the wheel from the road surface with lubricant. The water film fills the tiny potholes on the road surface, which seriously affects the embedding of the two. This phenomenon is called "water cushion". Water cushion can reduce the friction between the wheel and the road surface, and sometimes even make it close to zero, so that the driving, braking or steering of the car may fail. For an ordinary car with five passengers, the thickness is 0. 8 cm is only 0 on the road. When the speed reaches 90km/h, it is 100km /h, which is close to zero ... In rainy and snowy weather, the running car brakes may get water. The water permeating into the brake will form a water film on the surface of the brake shoe friction plate and the brake drum, which will play a certain role in lubrication, thus leading to the failure of automobile braking or the reduction of braking efficiency. In addition, the visibility is low in rainy days, and the driver's sight distance is relatively low, which is easy to cause accidents because he can't see the road ahead clearly. On the snowy road, due to the reflection of snow light, the driver's vision is tired and it is difficult to identify the road conditions.

(C) the impact of heavy fog on road traffic

Due to heavy fog, traffic accidents such as rear-end collision often occur, especially on highways and expressways. There are two traffic terms here-absolute safe distance and relative safe distance. The former refers to the sufficient distance between the rear car and the front car to avoid rear-end collision when the car is driving in the same lane on the road. The latter means that when the car is driving in the same lane on the road, the driver of the following car keeps a safe distance from the preceding car according to his own estimation of the road traffic situation, the performance, driving speed and his own traffic driving experience of the preceding car and the following car. Under normal climatic conditions, the visible distance on the road (especially on the expressway) depends on the absolute safe distance and the relative safe distance. Tested by the traffic safety management department, the distance between vehicles (m) is not less than the vehicle speed (km/h) under the condition of dry road surface and good braking. In a foggy climate, the perception of the severity of human fog by people with normal vision is not only related to the density of human fog, but also related to the change rate of human fog density and time. Generally speaking, the arrival process of human fog takes a certain time, that is, there is a transitional process, so it is difficult for drivers to accurately perceive or estimate the severity of human fog, just like people suddenly feel a dark place from a bright place. In addition, the climatic conditions in some expressway areas are complex and changeable, and the sight distance of different sections is different, so it is difficult for drivers to adjust the speed and spacing in time, which is easy to cause rear-end accidents.

(D) the impact of high temperature weather on road traffic

High temperature weather will have a great impact on vehicles, and it is easy to cause engine, brake and tire failures, thus leaving potential safety hazards. In high temperature environment, the heat dissipation of engine cooling system is weakened, and the engine is easy to overheat when the car is driving; Engine parts will also accelerate wear due to poor lubrication caused by high heat dilution of engine oil, and even lead to jamming or damage of parts; The heat dissipation of the brake will decrease in high temperature environment. After using the brake for a long time, the brake shoe friction plate will gradually accumulate heat and form high temperature. Under the action of high temperature, the friction coefficient between brake shoe friction plate and brake drum will decrease, resulting in poor braking. In the high temperature environment, the internal pressure of the tire will increase to a certain extent, the heat accumulated by the friction between the tire itself and the ground is not easy to dissipate, and the temperature of the tire itself will gradually increase. Once the tire internal pressure exceeds its rated air pressure, coupled with factors such as road bumps or overload, it is easy for a moving car to puncture. In addition, high temperature will also have an impact on the pavement, and asphalt pavement is easily softened by the heat of sunlight, reducing the friction coefficient between wheels and pavement. According to the test, even if the asphalt pavement is designed and constructed normally, at the speed of 60km/h, the friction coefficient will decrease with the increase of pavement temperature, which basically changes in a straight line. When the pavement temperature rises to 30℃, the friction coefficient will decrease by 1 /30.