Takeover Requests Signaled by Arrows in an Automated Driving System: The Influence of Information Direction and Lead Time on Performance

This study explored the impact of arrow cues in a head-up display (HUD) on takeover performance in a self-driving system. Experiment 1 investigated the effect of different cue types (arrow versus circle) on objective takeover performance and subjective evaluation in different takeover requests (TORs; toward-action versus toward-hazard) and lead time (4 s versus 7 s). Experiment 2 further investigated the different effect of single- and dual-message arrow cues. The results of experiment 1 showed that, compared with circle cues, arrow cues led to better performance in takeover tasks, as evidenced by both the objective measures and subjective evaluations. The results of experiment 2 revealed that single-message arrow cues outperformed dual-message cues. The study indicated that single-message arrow cues had better outcomes in the TOR tasks of a self-driving system, particularly when using toward-action TORs. Our findings have important implications for future TOR cue design in the HUD of automated driving systems.