基于交通流理论的山岭隧道接近段停车视距修正计算

速度是停车视距中最重要的计算参数,而现有停车视距模型的修正计算中较少考虑山岭隧道交通环境对车辆行驶速度的影响.为研究山岭隧道接近段速度流量特性,选取重庆具有代表性的4条山岭隧道开展交通观测现场实验.利用山岭隧道接近段车速和车流量数据,分析车流量和速度的时空特性分布规律与统计学关系,建立山岭隧道接近段车速和流量关系模型的...

Correction Computation of Stopping Sight Distance in Approaching Section of Mountain Tunnel Based on Traffic Flow Theory

Speed is the most important calculation parameter in stopping sight distance. However, the existing correction computation of the model of stopping sight distance does not consider the impacts of traffic environment in mountain tunnel on the driving speed. Four representative mountain tunnels in Chongqing are selected to carry out field experiments, thus studying characteristics of speed flow in the approaching section of mountain tunnel. The data of speed and traffic flow in the approach section is used to analyze the distribution law and statistical relationship of traffic flow and speed. Then a model of the relationship between vehicle speed and traffic flow in the approaching section is developed to derive the stopping sight distance formula based on the characteristics of speed flow. The values of relevant standards and norms are compared to reveal the law of change. The results show that the speed of the approaching section of the mountain tunnel decreases first and then increases. Traffic flow is significantly related to vehicle speed. After fitting, a calculation model with coefficient R2 =0.9 is obtained. At the same speed, the modified value is about 1.07 to 1.21 times of the standard value. The greater the speed, the greater the differences. The modified stoppingsight distance length can meet the needs of 70% drivers at least. Based on the corresponding regulations, the impacts of traffic flow on vehicle speed of the stopping sight distance is considered to improve the driving safety level in the approaching section of the mountain tunnel.