Influence of Information about Minimal Risk Maneuvers on Driver Behavior during Conditional Driving Automation

Abstract

In Japan, the guidelines of safety technology for automated vehicles clearly state the requirement of level-3 equipment with minimal risk maneuver (MRM) in automated vehicles. In case the drivers fail to respond to a request for intervention, the conditional driving automation system activates an MRM to control the vehicle to a halt in the driving lane or on the side of the road. The current study aims to explore the research question: how does the information of the MRM functionality equipped within the automated vehicle affect the driver behavior during conditionally automated driving? In this study, we hypothesized that drivers who are provided with information about MRM functionality may reduce their attention toward the surrounding environment. The attention allocation to the surrounding environment may be related to the quality of take-over performance. Therefore, we attempted to observe the drivers' takeover performance in response to RtI. Accordingly, a driving simulator experiment was conducted with 28 drivers as participants to investigate the influence of information regarding MRM on driver behavior. Two groups were formed by randomly placing the participants with and without providing MRM information. The results revealed that the information on MRM triggered a behavioral change in the drivers and reduced their attention toward the surrounding environment or allocated more attention toward the surrounding environment. In future, we would examine the method and content of communicating the MRM information to drivers using automated driving systems.