The Characteristics and Mechanism of Fog on Freeway: A Case Study of Chongqing, China

Prediction and early warning of fog events on freeways is essential for proactive traffic safety management under fog conditions. Understanding the characteristics and mechanism of fog on freeways is the basis for accurate and timely prediction of low visibility. This study aims to analyze the temporal distribution characteristics of fog events and explore the correlation between visibility and meteorological variables. Guanyinyan service area on the G50S freeway in Chongqing, China is chosen as the study case. The results indicate that: a) early morning (4:00 to 9:00) is the most frequent period of fog events, and most fog events last between 10 and 20 minutes, b) visibility level has a strong correlation with wind speed, humidity, air temperature and rainfall.