What does a black snowflake in the yellow triangle warning sign mean?

The black snowflake in the yellow triangle warning sign indicates that the road surface is icy.

Used to warn vehicle drivers to pay attention to icy roads and drive carefully.

Extended data:

1. What do you mean by road icing?

Road icing refers to the phenomenon that snow or ice appears during precipitation (such as rain, snow, freezing rain or fog drops, etc.). ) The touchdown temperature is lower than 0℃. It usually includes frozen residual snow, convex and concave ice ruts, snowmelt water or other hard ice layers formed by road water in cold season.

2. Under what circumstances does road icing generally occur?

Road icing is easy to occur from June 1 1 to April of the following year (that is, winter and early spring). Road icing often occurs in northern China, especially in the northeast and northern Inner Mongolia. In southern China, snowfall is generally "wet snow", which often belongs to mixed water of 0 ~ 4℃. When it falls to the ground, it will turn into ice water paste, and when the temperature drops at night, it will solidify into large pieces of ice. As long as the local minimum temperature in winter is lower than 0℃, there may be road icing, and as long as the temperature does not rise enough to melt the ice, it will remain as solid as a rock.

Generally speaking, in the cold winter, when the temperature drops due to a wide range of strong cold air activities (called cold wave in meteorology), if it is accompanied by rain and snow, it is most prone to road icing.

Third, the dangers of road icing.

When the road surface freezes, the friction between the wheels and the road surface is greatly weakened, and it is easy to skid and stop, causing traffic accidents. Pedestrians are also prone to slip and fall.

At the beginning of 2008, weather such as rain, snow and freezing continued to occur in more than a dozen provinces in southern China, which led to the closure of many highways due to snow and freezing on roads, and the closure of civil aviation airports due to a large amount of snow and freezing on airstrips and aprons, which made it impossible to transport people and materials, which had a serious impact on traffic.

Four, road icing warning signal release

When the road surface temperature is lower than 0℃, precipitation occurs, and road icing may occur within 12 hours, the meteorological department will issue a warning signal for road icing to the society. According to the time of appearance and the impact on traffic, it is divided into three grades, which are represented by yellow, orange and red respectively. In addition, we should also pay attention to the cold wave warning signal issued by the meteorological department to the society. The cold wave warning signal is divided into four levels, which are represented by blue, yellow, orange and red respectively.

5. How to get the warning signal of road icing?

There are several ways to know the warning information of road icing in advance: First, you can call1212/or consult the local meteorological station, or you can get the warning information through TV, radio, newspapers, the Internet, mobile phone messages, etc. You can also check the warning devices of road icing warning signals, such as warning signs, warning flags, warning lights, etc. You can also go to the weather website.

6. What should the relevant departments do when the road freezes?

Traffic, public security, public utilities and other departments and units should pay close attention to the local meteorological forecast and early warning information, and once the pavement temperature is found to be close to 0℃, salt should be evenly sprinkled on the pavement in time; When the road is covered with snow, organize manpower to clean it in time, or spray snow melting agent; If traffic accidents are caused by road icing, obvious warning signs should be set at the scene to prevent accidents from happening again; Pay attention to command and guide vehicles, and close icy roads if necessary.

7. How should drivers and friends drive when the road is frozen?

1, slow down. Drive according to the speed predicted on the expressway variable information display board to prevent the vehicle from slipping and shorten the braking distance.

2. Increase the distance between cars. The distance between vehicles on ice and snow pavement should be 2 ~ 3 times that of dry pavement.

3. Drive along the rut of the car in front. In general, don't overtake, accelerate, turn sharply or brake suddenly. When it is necessary to stop, measures should be taken in advance to shift gears more and brake less to prevent sideslip caused by various reasons.

4. When driving on a curve or ramp with ice and snow, you should slow down in advance.

5. Install tire chains in time or switch to snow tires.

8. What should people pay attention to when they encounter road icing?

1, keep warm when going out, and try not to expose the parts that are easy to be frostbitten, such as ears, hands and feet;

2. Pedestrians should be careful when going out and put on non-slip shoes;

3. Residents should not go out at will, especially to ride bicycles less;

4. Ensure that the old, the young, the sick and the weak stay at home;

5, because of the icy road slip, fall, careless fracture, should do emergency treatment such as dressing, fixation.

Nine, special tips for students

1, cross the road to obey the traffic police command and guidance;

2. It is recommended to ride less or not ride a bike to school;

3. Educate students not to play in the frozen playground or open space;

If you skate, you must take protective measures.

China Meteorological Bureau-Road icing and its early warning