Comparative analysis of two rainfall/snowfall and freezing weather events impact on the highway in early 2024

In early 2024, from January 31 to February 5 and from February 18 to 25,two widespread rainfall/snowfall and freezing events weather occurred in China,hereinafter referred to as the "0131" and "0218" events. The two events were characterized by complex precipitation phases,large amounts of rainfall and snowfall,a wide range of influence,and long duration. Utilizing the observation data from 2 430 national weather stations,as well as the traffic volume and highway block information,the impact characteristics of the two rainfall/snowfall and freezing weather events on highway traffic were compared and analyzed. In addition,the snowfall,freezing rain,snow depth,surface ground temperature,and surface ground ice were selected as the elemental indexes affecting highway traffic. Then an ice and snow weather index was constructed to explore the relationship between the intensity of ice and snow weather and the impact on highway traffic. The results indicate that the two weather events occurred during the peak periods of people traveling to their hometowns before the Spring Festival and returning after the festival. The "0218" event had a wider impact range,resulting in a higher overall reduction in traffic flow compared to the "0131" event. During the two events,the highway traffic in Shaanxi,Shanxi,Henan,Hubei,Hunan,and Guizhou was severely affected by snow accumulation or ice,with many road section closures. However,there were regional differences in the degree of impact. Specifically,the "0131" event had a stronger impact on Shanxi,Henan,Hubei,and Hunan. While the "0218" event had a more significant impact on Shaanxi and Guizhou. During the two events,the intensity of the ice and snow weather index was consistent with the trend of impact degree of road blockage,and inversely proportional to the rate of change in traffic volume,indicating that the ice and snow weather index has a good guiding significance for the assessment of the impact of rain and snow freezing weather on highway traffic.