Study on Evaluation for Crowd Degree of Traffic Flow at Urban Tunnel Access Based on Acceleration Noise

Abstract

In order to study the running state of the traffic flow that occurred at urban tunnel access, the urban tunnel traffic flow was taken as the object of the study. Then the dynamic accelerations of traffic flow in Xuanwu Lake tunnel, Drum-tower tunnel, and Jiuhua Mountain tunnel were investigated by the texting vehicle method, and the acceleration noise values of different tunnels’ traffic flow were calculated and analyzed based on computational model of acceleration noise. On the basis of data, the graphed relationship between the traffic flow state and acceleration noise by the simulation approach was obtained. According to the graphed different operating characteristics of vehicles, the level-of-service of unidirectional two-lane at urban tunnels was categorized into four classes; and the corresponding value range of average travel speed was determined. The results about the traffic congestion that gained by using evaluation indicators of acceleration noise would provide references of the engineering practices.