Auditory Driver Distraction during SAE Level 2 Automated Driving

Commercially available automated vehicles require drivers to remain attentive to the driving environment and be prepared to assume full control of the vehicle (i.e., perform a takeover) when critical incidents occur (e.g., sudden automation failures). Consequently, drivers are discouraged from engaging in non-driving tasks that cause visual or manual distractions. Although auditory interactions are often regarded as a safer alternative, they can nonetheless consume drivers' attentional resources, potentially impairing their responses to critical situations. This project investigated the extent to which various auditory interactions influence drivers' takeover performance during SAE Level 2 automated driving. To this end, we developed a low-cost, in-lab SAE Level 2 driving simulator, selected auditory and visual secondary tasks, and recruited 50 participants to measure takeover performance alongside multiple physiological signals and self-reported workload. The results indicate that, while the impact of auditory tasks was less pronounced than that of visual tasks, high-workload auditory tasks nonetheless decreased takeover performance. Furthermore, the findings demonstrate the feasibility of detecting such impairments through physiological signals. Additionally, when engaged in auditory tasks, drivers exhibited behavior changes indicative of reduced resource allocation to secondary tasks under high-workload conditions.