高速公路隧道入口区域轨迹突变现象分析与调节方法

An Analysis and Adjustment of the Abrupt Change of Vehicle Trajectories in the Entrance area of Freeway Tunnels

行车轨迹在高速公路隧道入口区域会发生突变。为分析这个现象产生的原因,并定量评价不同视线诱导方案的调节作用,构建了4个仿真场景。场景1为对照组,参照JTG D70/2—2014《公路隧道设计规范第二册交通工程与附属设施》设置,其他场景在场景1的基础上增设视线诱导方案。具体而言:场景2增设低位方案(弹性交通柱+防撞桶);场景3增设高位方案(反光环+警示型线形诱导标);场景4增设组合式方案(低位+高位)。通过模拟驾驶平台获得行驶距离、方向盘角度、横向偏移等数据,并根据轨迹突变现象的发生、演变和消退,构建评价指标体系。研究结果表明:视觉参照系突变会导致行车轨迹突变,连续一致的视线诱导方案可以调节这一现象。具体而言,与对照组相比,低位方案的突出效果是使洞门前的方向盘转角(SWAav)减少了82%,有助于减缓驾驶人对洞门的规避动作;高位方案的突出效果是使渐变系数(G)提高了3.7倍,短暂稳定段的期望横向偏移(O1)减少了31%,以及O1与稳定段期望横向偏移(O2)的差值(O1-O2)减少了75%,从而提高了轨迹的渐变性,减弱了对隧道侧壁的规避,并提升了对隧道内环境的适应性;组合式方案结合了低位和高位方案的优点,使G提高了4.4倍,SWAav减少了83%,O1减少了41%,O1-O2减少了98%,在提高轨迹变化段的渐变性,减弱对洞门的规避动作、对隧道侧壁的规避效应以及提高对隧道内环境适应性方面均表现最佳。因此,建议在高速公路隧道入口区域增设组合式方案,特殊情况可仅增设高位方案。

Vehicle trajectories would undergo abrupt changes at the entrance area of freeway tunnels.To analyze the reasons behind this phenomenon and quantitatively evaluate the regulating effect of different visual guiding schemes,four simulation scenarios are developed.Scenario 1,based on the guidelines outlined in Specifications for Design of Highway Tunnels Section 2 Traffic Engineering and Affiliated Facilities(JTG D70/2—2014),serves as the control group,while other scenarios incorporate visual guiding schemes on the basis of Scenario 1.Specifically,Scenario 2 introduces a low-position scheme consisting of flexible posts and crash cushions,Scenario 3 introduces a high-position scheme comprising retroreflective arches and warning alignment signs,and Scenario 4 combines both the low and high schemes.Through a simulated driving platform,data such as driving distance,steering wheel angle,and lateral offset are obtained,and an evaluation index system is established considering the occurrence,evolution,and fading of the abrupt change trajectories.The study results indicate that changes of the visual reference system can prompt abrupt changes of driving trajectories,but a continuous and consistent visual guiding scheme can regulate this phenomenon.Specifically,compared to the control group,the low-position scheme significantly reduced the average steering wheel angle before the tunnel entrance(SWAav)by 82%,helping drivers avoid abrupt maneuvers.High-position scheme increased the gradient coefficient(G)by 3.7 times,reduced the expected lateral deviation during the transient stability phase(O1)by 31%,and decreased the difference between O1 and the expected lateral deviation during the stable phase(O1-O2)by 75%.This improved the gradual change in trajectory,reduced avoidance of the tunnel portal and wall,and enhanced adaptation to the tunnel environment.The combined guiding scheme,which integrates both low and high-position scheme,yielded the best results:it increased G by 4.4 times,reduced SWAav by 83%,decreased O1 by 41%,and minimized O1-O2 by 98%.This scheme effectively improved the gradual nature of trajectory changes,reduced avoidance of the tunnel entrance and walls,and enhanced environmental adaptation.Consequently,it is recommended to implement the combined scheme in the entrance areas of highway tunnels,with the exception of special cases where only the high scheme should be applied.