The Analysis of Traffic Flow Characterizes for Heavy Highway on Rainy Days

With the development of economy, highways play an important role in transportation system, especially for heavy highways. In order to learn traffic flow characterizes of heavy highway on rainy days, this study focuses on a heavy highway, Xuanda Highway, in Hebei Province. The research selects traffic data of seven days, collected by weigh-in-motion (WIM) system at Haierwa Bridge, to analyse the effect of rain on traffic flow characterizes, including volumes and speed. Specific issues evaluated that the traffic volumes were not sensitive to little rain, while speed of each time period has different degree of reduction during rainy days. The research further indicates people’s willingness to travel. In addition, the study quantifies the speed characteristics for each class, and the relationship between speed and heavy vehicle ratio on rainy days. 