Research on Traffic Flow Characteristic Parameters of Urban Road Sections in Adverse Weather Conditions

摘要

Taking Beijing urban road as the main object, relationships between weather conditions and traffic flow parameters were analyzed with fixed detector data, video data, and meteorological data. The independent-samples T-test was applied to verify that the difference of road type, road alignment design, number of lanes, and section position would result in different influence on traffic flow parameters. Then various sections were chosen to describe the traffic flow characteristics in different weather conditions. This paper used the method of nonlinear regression to estimate the traffic capacity and speed at capacity by calibrating model. The reduction ratio of traffic flow characteristic parameters was calculated in different intensity of rainfall and snowfall conditions. The results showed that free-flow speed of the expressway and arterial road was influenced by snowy weather more significantly than rainy weather. In the same precipitation intensity, the speed of the road with more lanes was affected the most.