Investigation of Driving Behavior at Alternative Intersection Designs and Safety Improvement: A Driver Simulator Study

Alternative intersection designs have been proposed due to their theoretical expected ability to simultaneously enhance traffic safety and operation as a result of reducing the number of conflict points and signal phases. However, this was only achieved at very limited intersection designs which have a very low number of conflict points and under certain traffic conditions. For example, the restricted crossing U-turn (RCUT) intersection, which has the lowest number of conflict points among other proposed intersection designs, has operational advantages at extremely unbalanced traffic volumes. Our shifting movement (SM) intersection design, which has the same number of conflict points as the RCUT intersection, has been proposed to replace the RCUT implementation at intersections with medium to high minor traffic volumes. It was proven that it outperforms the RCUT intersection which has medium to high minor traffic volumes in terms of average delay and throughputs. This study aimed to investigate the safety aspects of this intersection design by utilizing the driving simulator. The effectiveness of using infrastructure to vehicle (I2V) communication for mitigating the confusion at alternative intersections was also investigated in the study. The results indicated that RCUT and SM intersections have similar safety performance and crossing them is safer than crossing the conventional intersection. However, there is a need to improve drivers’ knowledge about the SM intersection, especially regarding the major left-turn movement. Most participants have found that using I2V communication is helpful in understanding the unconventional movement patterns.

现有研究已提出多种新型交叉口设计方案，其理论优势在于通过减少冲突点数量与信号相位时长，可同时提升交通安全水平与通行效率。然而此类优势仅能在冲突点极少的少数交叉口设计，以及特定交通工况下得以实现。例如，受限穿越掉头（Restricted Crossing U-turn, RCUT）交叉口作为已提出的各类新型交叉口设计中冲突点最少的方案，在交通流量极度失衡的场景下具备通行优势。本研究提出的移位运行（Shifting Movement, SM）交叉口设计，其冲突点数量与RCUT交叉口一致，旨在替代RCUT方案应用于次要交通流量中至高的交叉口场景。经验证，在次要交通流量中至高的场景下，该设计在平均延误与通行吞吐量方面均优于RCUT交叉口。本研究旨在借助驾驶模拟器，对该新型交叉口设计的安全性能展开研究，同时探究车路协同（Infrastructure to Vehicle, I2V）通信用于缓解驾驶员在新型交叉口处通行困惑的有效性。研究结果表明，RCUT与SM交叉口的安全性能相近，且通过此类交叉口比通过常规交叉口更为安全。但仍需提升驾驶员对SM交叉口的认知水平，尤其是针对主要左转运行流程的相关知识。多数参与实验的人员表示，借助I2V通信有助于理解该新型交叉口的非常规运行模式。