Drive first or yield? Effect of complexity on cooperation behavior at deadlock-situations at T-intersections

Abstract

Deadlock-situations at intersections, where the right-of-way is not clearly regulated, pose challenges for automated vehicles (AVs) in mixed traffic. For AVs to show behavior that is accepted by all traffic participants, it is important to understand the cooperation behavior of manual drivers in these situations. Three studies were conducted where the effect of complexity on cooperation behavior at deadlock-situations was examined. Participants watched videos of approaches to T-intersections where a deadlock-situation occurred but was not yet resolved. After each video they reported their intended behavior, the perceived difficulty and visual clutter of the situation as well as the anticipated behavior of the cooperation vehicles. Complexity was manipulated with visual built clutter, pedestrians and additional traffic. Results show minimal effect of complexity on perceived difficulty and visual clutter as well as cooperation behavior. However, cooperation behavior was significantly influenced by approach position. When approaching from below drivers are more likely to yield compared to approaches from left or right. Additionally, when a vehicle is driving through the intersection directly in front of the driver they show higher probabilities of driving first through the intersection. The anticipated behavior of the cooperation vehicles is influenced both by their approach position and the right-of-way rule from the driver’s perspective, suggesting that the right-of-way rules are not correctly understood and therefore the deadlock-situation is not recognized as such. Recommendations for the behavior of automated vehicles in these situations are derived from the findings of the studies.