Interacting with pedestrians understandably and efficiently is one of the toughest challenges faced by autonomous vehicles (AVs) due to the limitations of current algorithms and external human-machine interfaces (eHMIs). In this paper, we design eHMIs based on gestures inspired by the most popular method of interaction between pedestrians and human drivers. Eight common gestures were selected to convey AVs' yielding or non-yielding intentions at uncontrolled crosswalks from previous literature. Through a VR experiment (N1 = 31) and a following online survey (N2 = 394), we discovered significant differences in the usability of gesture-based eHMIs compared to current eHMIs. Good gesture-based eHMIs increase the efficiency of pedestrian-AV interaction while ensuring safety. Poor gestures, however, cause misinterpretation. The underlying reasons were explored: ambiguity regarding the recipient of the signal and whether the gestures are precise, polite, and familiar to pedestrians. Based on this empirical evidence, we discuss potential opportunities and provide valuable insights into developing comprehensible gesture-based eHMIs in the future to support better interaction between AVs and other road users.

翻译：由于当前算法和外部人机界面（eHMI）的限制，与行人进行可理解且高效的交互是自主车辆（AVs）面临的最严峻挑战之一。本文基于行人与人类驾驶员最常用的交互方式，设计了基于手势的eHMI。从以往文献中选取了八种常见手势，用于在无信号控制人行横道处传递AVs的让行或不让行意图。通过一项虚拟现实实验（N1=31）和后续在线调查（N2=394），我们发现基于手势的eHMI在可用性上与当前eHMI存在显著差异。良好的基于手势的eHMI能在确保安全的同时提高行人-AV交互的效率，而糟糕的手势则会导致误解。我们探讨了背后的原因：信号接收者的模糊性，以及手势是否准确、礼貌且为行人所熟悉。基于这一实证证据，我们讨论了潜在机遇，并为未来开发可理解的基于手势的eHMI以支持AVs与其他道路使用者之间更好的交互提供了宝贵见解。