Time to Focus on the Road: Adaptive Monitoring Requests Design for Attentional Shift in Conditional Automated Driving

In conditional automated driving, drivers may perform non-driving related tasks (NDRTs) but remain responsible for supervising the driving environment. A monitoring request (MR) redirects attention from NDRTs to the road before possible take-over situations. This study aims to design an adaptive MR interface that optimizes interruption, reaction, and comprehension (IRC) based on urgency and criticality in traffic contexts. A driving simulator study assessed participants’ perceived needs for interruption, reaction, and comprehension while performing dual tasks involving both NDRTs and monitoring tasks. Results showed that drivers’ interruption and reaction needs increased in high-urgency situations, while they preferred lower levels of both in low-urgency contexts. Comprehension remained consistently high across all scenarios, reflecting their strong desire for a broad understanding of driving risks. Based on these findings and insights from the interview, we finally propose an adaptive MR interface to enhance human–automated vehicle collaboration.