隧道与互通出口小净距路段换道可靠性研究

Research of Lane Changing Reliability on Short Distance Section Between Tunnel and Interchange Exit

为分析高速公路隧道与互通出口小净距路段在不同交通流状况下的车辆驶出概率,提出了基于交通仿真的安全换道概率模型。首先,采用VISSIM标定仿真模型并进行正交试验,获取小净距路段在不同净距长度、交通量、驶出比例、大型车比例下的交通数据,在此基础上确定瞬时交通流密度及相应车流平均速度的计算方法,构建相应的分布模型,通过K均值聚类算法研究不同速度下的瞬时交通流密度大小和出现概率;同时引入可靠度方法并利用微分法来构建车辆安全换道概率模型,综合考虑车速、车流密度、目标车道临界可插入间隙等因素的不确定性,应用蒙特卡罗仿真法搭建求解概率模型的算法,并通过MATLAB对模型进行求解;针对分流车初始位置的不同,分别得到了不同交通量、大型车比例、净距长度下的换道驶出成功率,进而研究不同交通流状况组合下的净距长度。结果表明:交通量、大型车比例、净距长度对净距路段内侧车道车辆换道驶出成功率有显著性影响,研究结果可为规范的进一步完善提供参考。

To analyze the vehicle exit probability of expressway tunnels and interchange exits with small clear distances under different traffic flow conditions, this study proposes a safe lane change probability model based on traffic simulation. First, VISSIM was used to calibrate the simulation model and conduct orthogonal experiments to obtain traffic data from small clear distance sections under different clear distance lengths, traffic volumes, driving out and large vehicle ratios. On this basis, the instantaneous traffic flow density calculation method and the average speed of the corresponding traffic flow was determined, the corresponding distribution model was constructed, and the instantaneous traffic flow density and occurrence probability under different speeds were studied using the K-means clustering algorithm. The reliability method was introduced, and the differential method used to build the probability model of vehicle safe lane change. Considering uncertainties in vehicle speed, traffic density, target lane critical insertable gap, and other factors, the Monte Carlo simulation method was used to build the probability model algorithm, which was solved using MATLAB. Based on shunting vehicle different initial positions, the lane change success rate under different traffic volumes, large vehicle ratios, and clear distance lengths was obtained. Subsequently, the clear distance length under different traffic flow conditions was investigated. The results demonstrate that traffic volume, proportion of large vehicles, and clear distance length have a significant impact on the success rate of lane-changing vehicles in the clear distance section, which provides a reference point for further improvement of the specification.