The More You Know, The More You Can Trust: Drivers' Understanding of the Advanced Driver Assistance System

Suggestions for improving the drivers' understanding and trust in the advanced driver assistance system (ADAS) are proposed. A user survey and an in-depth interview were conducted to investigate what information the drivers should receive from the system to gain trust in ADAS. Results obtained from the user survey indicate that not only the general public but also experts lacked understanding of the system behaviour under automatic operation. In particular, drivers lacked understanding of the 'temporary mode disengagement' and 'restricted range of operation'. Results obtained from the in-depth interview indicate that drivers require information on the system operation if it acts differently from the user's expectation. The suggestions in this study were refined based on insights from the qualitative analysis. The key result was interpreted by the theoretical study of Donald Norman's 'seven stages action model' and 'mental model'. Moreover, we determined the drivers' need for information on the status of the system and the reasons behind its automatic operations. We sorted the system's automatic operations into 'temporary mode disengagement', 'restricted range of operation', 'detection of the front car of adaptive cruise control (ACC)', and 'failure of lane detection of lane-keeping assist (LKA)'. Providing information enables drivers to understand the system's automatic operation and general purpose. The findings in this study provide an approach to form the right mental model for drivers when employing ADAS. We expect that our findings will be of help to design ADAS user interface increasing trust and safety.