Analysis of Traffic Flow Characteristics under Large Volume in Highway Tunnel Group Region

Based on the field monitoring data of traffic flow in a typical highway tunnel group region, the traffic flow characteristics were analyzed with statistical analyzing method of the relationship among the speed, volume and density of the traffic flow. The result shows that the traffic capacity in highway tunnel group region was mainly controlled by the traffic volume, the traffic flow component and so on. The existing methods in present code could not reflect the real situation of the traffic flow under large traffic volume in the highway tunnel group region. The paper investigated the passenger car equivalent with method of vehicle headway analysis based on field monitoring data. Then the traffic capacity and the service level were re-evaluated on the results of above new passenger car equivalent. The results reflect the real traffic situation in the highway tunnel group area better than the method provided in the existing code. The data and results presented in the paper can be used for further analysis of the traffic flow in the highway tunnel group area and for the purpose of corresponding code revision.