HMI Design when Using Level 2 Automated Driving Function - Effects of System Status Presentation Considering the Risk of Malfunction on Driver Behavior

This study examined the effect of system status presentation on driver behavior when driving with ACC and LKA, which are classified as level 2 automated driving. First, we analyzed the driving behavior of 40 test participants in a driving simulator study under three HMI conditions: without safety level, correct safety level, and incorrect safety level which does not work properly and becomes inactive. The driver behavior database constructed in this experiment, was used to quantify the accident avoidance probability under each HMI condition using the state transition probabilistic model proposed by the author in a previous study. Finally, we quantified the degree of reduction in the probability of accident occurrence when using this HMI device in consideration of the risk of malfunction based on the integrated error model proposed by the author. Based on these results, it was shown that the HMI device that acts as a real-time interface at the system safety level between the driver and the automated driving using ACC and LKA is effective in reducing traffic accidents regardless of the increased probability of traffic accidents due to malfunctions of HMI device.