The Effects of Cyclists Present at Rural Intersections on Speed Behavior and Workload of Car Drivers: A Driving Simulator Study

Objective: The objective was to gain insight into how the number of cyclists, the cyclist's approach direction, and the cyclist's action affect the speed and mental workload of drivers approaching rural intersections. In addition, the effects of a speed-reducing measure on the interaction between cyclists and motorized traffic were examined. Methods: An experiment was conducted in a moving-base driving simulator. Thirty participants completed 3 runs each in 3 conditions: a baseline, a plateau, and a chicane condition. Participants drove an 80 km/h rural distributor road with 8 intersections. Eight cyclist scenarios were developed varying in the number of cyclists and the direction from which they approached the participants’ lane. The Peripheral Detection Task was used to measure workload objectively and continuously. Results: A plateau ahead of the intersection resulted in drivers entering the bicycle crossing with lower driving speeds but did not result in less serious potential conflicts compared to intersections without the speed-reducing measure. With respect to the presence of cyclists, drivers approaching the intersection without cyclists reached a minimum speed at a greater distance from the bicycle crossing compared to approaching the intersection with multiple cyclists in the baseline condition. At intersections with plateaus, drivers drove slower when encountering multiple cyclists compared to no cyclists. At intersections without the speed-reducing measure, drivers drove slower, decelerated stronger, and decelerated at a shorter distance to the bicycle crossing when encountering a suddenly crossing cyclist compared to a yielding cyclist. Conclusions: Although drivers have the right of way at rural intersections, drivers’ speed behavior was affected by the number and action of cyclists. From a road safety point of view, driving speeds at rural intersections need to be further reduced to limit the seriousness of potential conflicts between cyclists and motorized traffic.

研究目标：本研究旨在深入探究骑行者数量、骑行者接近方向以及骑行者行为，如何影响接近乡村交叉口的驾驶员的行驶速度与心理工作负荷。此外，本研究还考察了一项减速措施对骑行者与机动车交通之间交互行为的影响。
研究方法：本研究基于移动基座驾驶模拟器开展实验。30名受试者分别在基线（baseline）、减速台（plateau）与迂回减速弯道（chicane）三种条件下各完成3次试验。受试者驾驶一条限速80 km/h的乡村集散道路，该道路共包含8处交叉口。研究设计了8种骑行者场景，通过改变骑行者数量以及其接近受试车辆所在车道的方向，实现场景差异化。本研究采用外周视觉检测任务（Peripheral Detection Task）客观且持续地测量驾驶员的心理工作负荷。
研究结果：相较于未设置减速措施的交叉口，在交叉口前设置减速台可使驾驶员以更低的车速驶入自行车过街横道，但并未降低潜在冲突的严重程度。就骑行者存在与否而言，在基线条件下，当交叉口无骑行者时，驾驶员会在距离自行车过街横道更远的位置达到最低行驶速度；而当交叉口存在多名骑行者时则呈现相反趋势。在设置减速台的交叉口处，相较于无骑行者的场景，驾驶员在遭遇多名骑行者时会以更低的车速行驶。在未设置减速措施的交叉口，相较于礼让的骑行者，当遇到突然横穿的骑行者时，驾驶员会以更低的车速行驶、实施更强程度的减速，且会在距离自行车过街横道更近的位置开始减速。
研究结论：尽管乡村交叉口处机动车享有优先通行权，但驾驶员的车速行为仍会受到骑行者数量与行为的影响。从道路交通安全视角出发，需进一步降低乡村交叉口处的行驶车速，以限制骑行者与机动车交通之间潜在冲突的严重程度。