Yang Yonghong, Hu Yixi, Xu Chuangbo, Zhang Yu, Zheng Tao
School of Civil Engineering and Transportation, South China University of Technology, Guangzhou, China; Guangdong Provincial Key Laboratory of Tunnel Safety and Emergency Support Technology & Equipment, Guangzhou, China.
School of Civil Engineering and Transportation, South China University of Technology, Guangzhou, China.
Accid Anal Prev. 2025 May 2;218:108082. doi: 10.1016/j.aap.2025.108082.
Previous research has indicated that freeway tunnel portals are prone to traffic accidents, with alignment at tunnel portal being a significant factor influencing crash occurrence. However, how to ensure safe design of freeway tunnel portal alignment remains unclear. This study developed a freeway model with five tunnels, whose portals are located at different positions along a tangent-curve section, to comprehensively investigate the impact of portal locations on driving behavior and traffic safety. Microscopic driving parameters were obtained through experiments and further analyzed using reliability analysis. Based on real-world crash data, two failure modes were considered: insufficient stopping sight distance and excessive lane departure. The probability of failure (PoF) was calculated using the Monte-Carlo sampling algorithm as an effective indicator of driving risk. To further explore various features affect tunnel portal traffic safety, sensitivity analysis was conducted on four key indicators, include curve radius, spiral length, pavement friction coefficient, and driving speed. The results show that the design locations of the tunnel portal significantly affect drivers' speed and lane departure behavior. When the portal is located on a tangent section, the distribution of driver speed and lane departure behavior are the most concentrated. In contrast, when the portal is situated on a circular curve or spiral section, the distribution becomes more dispersed. The failure modes and PoF are related to the portal location. Besides, the PoF based on insufficient stopping sight distance increases continuously with the curvature at the portal, while the PoF based on excessive lane departure increases with the deviation of curvature. The synthetic PoF indicates that when the portal is located 3/4 of the spiral section, the PoF is the highest, reaching up to 35.66% at the entrance and 25.31% at the exit. The curve radius, spiral length, pavement friction coefficient, and driving speed all influence the PoF at the tunnel portal. Among these factors, increasing the curve radius and ensuring a sufficient pavement friction coefficient have the most significant impact on reducing the PoF. This study proposes recommendations for the alignment design of freeway tunnel portals and traffic safety management, providing valuable references for road designers and freeway administrators to enhance the traffic safety of freeway tunnels.
先前的研究表明，高速公路隧道入口容易发生交通事故，隧道入口处的线形是影响碰撞事故发生的一个重要因素。然而，如何确保高速公路隧道入口线形的安全设计仍不明确。本研究建立了一个包含五条隧道的高速公路模型，其入口位于切线-曲线段沿线的不同位置，以全面研究入口位置对驾驶行为和交通安全的影响。通过实验获得微观驾驶参数，并使用可靠性分析进行进一步分析。基于实际碰撞数据，考虑了两种失效模式：停车视距不足和车道偏离过大。使用蒙特卡洛抽样算法计算失效概率（PoF），作为驾驶风险的有效指标。为了进一步探究影响隧道入口交通安全的各种特征，对四个关键指标进行了敏感性分析，包括曲线半径、螺旋长度、路面摩擦系数和行驶速度。结果表明，隧道入口的设计位置显著影响驾驶员的速度和车道偏离行为。当入口位于直线段时，驾驶员速度和车道偏离行为的分布最为集中。相比之下，当入口位于圆曲线或螺旋段时，分布变得更加分散。失效模式和PoF与入口位置有关。此外，基于停车视距不足的PoF随着入口处曲率的增加而持续增加，而基于车道偏离过大的PoF随着曲率偏差的增加而增加。综合PoF表明，当入口位于螺旋段的3/4处时，PoF最高，入口处高达35.66%，出口处为25.31%。曲线半径、螺旋长度、路面摩擦系数和行驶速度均会影响隧道入口处的PoF。在这些因素中，增加曲线半径和确保足够的路面摩擦系数对降低PoF的影响最为显著。本研究为高速公路隧道入口的线形设计和交通安全管理提出了建议，为道路设计者和高速公路管理者提高高速公路隧道的交通安全提供了有价值的参考。
