Abstract The current study addressed the issue of designing request-to-intervene (RtI) of a level 3 automated driving system. We hypothesized that providing the driver with step-by-step operating instructions and surrounding traffic environmental information in the RtI message could smooth driver takeover performance and enhance safety. To test this hypothesis, we conducted an experiment with a driving simulator. In the experiment, 40 participants were divided into four Human-Machine Interface (HMI) groups: Beeps HMI (Baseline), Operating Instruction HMI, Environmental HMI, and Combined HMI. The results revealed that both additional operating instructions and environmental information could lower the steering wheel reversal rate. The combination of operating instructions and surrounding traffic environmental information contributed to reducing the accident rate.