Core Viewpoint - The article discusses the characteristics of fog, its impact on driving safety, and provides guidelines for safe driving in foggy conditions. Group 1: Characteristics of Fog - Fog is a visible collection of tiny water droplets or ice crystals suspended in the atmosphere, reducing horizontal visibility to less than 1 km [1] - Common types of fog include radiation fog, advection fog, upslope fog, and evaporation fog, each formed under different conditions [2][3] - The article highlights the specific concern of "group fog," which has visibility below 200 meters and poses significant risks to road traffic [4] Group 2: Fog Warning Levels - Meteorological departments classify fog into different warning levels based on visibility, including light fog, heavy fog, and severe fog [5][6] - When visibility drops below 500 meters, a yellow warning is issued, and further warnings are escalated as visibility decreases [5] Group 3: Temporal and Spatial Distribution of Fog - Fog distribution in China shows significant regional and seasonal variations, with areas like the Yangtze River basin and coastal regions experiencing more fog days [10] - Seasonal patterns indicate that fog is more prevalent in autumn and winter, particularly in regions with high humidity [11] - Most fog occurs at night and in the early morning, with a peak occurrence between 5 AM and 7 AM [12] Group 4: Impact of Fog on Driving Safety - Fog is one of the most hazardous weather conditions affecting traffic safety, with higher accident rates compared to rain or snow [13] - Data from the U.S. shows that in 2023, fog-related accidents resulted in 399 fatalities, highlighting the severe risks associated with driving in fog [13] Group 5: Challenges for Drivers - Reduced visibility in fog limits drivers' ability to gather visual information, leading to decreased operational precision [15][16] - Psychological stress increases under foggy conditions, causing drivers to misjudge distances and react slower, significantly raising accident risks [17] Group 6: Vehicle Performance in Fog - Fog affects vehicle performance, particularly braking systems, due to reduced road traction and increased stopping distances [19][20] - Lighting systems struggle in fog, as standard headlights lose effectiveness, and the use of high beams can create dangerous glare [21][23] Group 7: Traffic Environment Risks - Highways are particularly vulnerable to fog-related accidents due to sudden visibility drops, leading to multi-vehicle collisions [27] - Rural and mountainous roads face compounded risks due to inadequate infrastructure and complex traffic conditions [28] - Bridges and tunnels present unique challenges in fog, with sudden visibility changes and slippery surfaces increasing accident likelihood [30] Group 8: Safe Driving Strategies in Fog - Drivers are advised to monitor weather forecasts and adjust travel plans accordingly to avoid driving in dense fog [35][36] - Techniques for assessing visibility, such as using road markings and distance markers, can enhance safety during foggy conditions [39][41] - Proper use of vehicle lighting and maintaining safe distances are critical for reducing accident risks in fog [50][54]