Effect of Takeover Guidance and Surrounding Traffic Information Affect Takeover Performance in Conditional Driving Automation

With the increasing number of vehicles equipped with conditional driving automation entering the market, it has become important to address the topic of improving driver takeover performance. This study focuses on designing the request to intervene (RtI) under conditional driving automation. We investigated takeover guidance and surrounding traffic information in the RtI influent takeover performance by conducting a driving simulator experiment. 32 participants were divided into four different groups based on the RtI design. The results show that adding surrounding traffic information to the RtI improves the safety of takeover performance. However, the combination of surrounding traffic information and takeover guidance impairs the takeover performance quality. Although all types of additional content (takeover guidance, surrounding traffic information, combination of takeover guidance, and surrounding traffic information) did not increase the participants’ workload during takeover, the participants gave a higher rating to the usability of the surrounding traffic information than the combination. This study demonstrates the importance of providing surrounding traffic information in RtI and the effectiveness of the system usability scale (SUS) in evaluating RtI designs.