Level 3 automated driving systems (ADS) have attracted significant attention and are being commercialized. A Level 3 ADS prompts the driver to take control by requesting to intervene (RtI) when its operational design domain (ODD) or system limitations are exceeded. However, complex traffic situations may lead drivers to perceive multiple potential triggers of RtI simultaneously, causing hesitation or confusion during take-over. Therefore, drivers must clearly understand the ADS's system limitations to understand the triggers of RtI and ensure safe take-over. In this study, we propose a voice-based HMI for providing RtI trigger cues to help drivers understand ADS's system limitations. The results of a between-group experiment using a driving simulator showed that incorporating effective trigger cues into the RtI enabled drivers to comprehend the ADS's system limitations better and reduce collisions. It also improved the subjective evaluations of drivers, such as the comprehensibility of system limitations, hesitation in response to RtI, and acceptance of ADS behaviors when encountering RtI while using the ADS. Therefore, enhanced comprehension resulting from trigger cues is essential for promoting a safer and better user experience using ADS during RtI.

翻译：三级自动驾驶系统已引起广泛关注并逐步实现商业化。当超出其运行设计域或系统能力范围时，三级自动驾驶系统会通过发出接管请求提示驾驶员接管控制权。然而，复杂的交通场景可能导致驾驶员同时感知到多个潜在的接管请求触发因素，从而在接管过程中产生犹豫或困惑。因此，驾驶员必须清晰理解自动驾驶系统的能力边界，才能准确识别接管请求的触发机制并确保安全接管。本研究提出一种基于语音的人机界面，通过提供接管请求触发线索来帮助驾驶员理解自动驾驶系统的局限性。基于驾驶模拟器的组间实验结果表明，在接管请求中融入有效的触发线索能使驾驶员更好地理解自动驾驶系统的能力边界，并降低碰撞发生率。该设计同时改善了驾驶员的主观评价指标，包括系统局限性的可理解性、响应接管请求时的犹豫程度，以及使用自动驾驶系统时遭遇接管请求对其行为模式的接受度。由此可见，通过触发线索增强驾驶员对系统局限性的认知，对于提升接管请求期间自动驾驶系统的安全性与用户体验具有重要意义。