Supporting Users' Understanding of Driving Automation Systems: The Effect of Meaningful System Names and Responsibility-Focused Textual Reminders

Abstract

Implicit demands on drivers are growing with today’s available variety of sustained driving automation systems: Drivers must understand each system’s function, limitations and their own corresponding role. Compared to the strong emphasis on the technical requirements of driving automation (e.g., outlined in international provisions concerning the approval of vehicles equipped with driving automation systems), the process by which users learn about and adapt to their emerging roles have not been explored to the same extent. This study examines how Human-Machine-Interface (HMI) design can enhance drivers’ role understanding as part of mode awareness across different SAE levels of driving automation, and was conducted in preparation for a larger on-road study. Thirty-seven lay participants were assigned to one of two sets of HMIs for different sustained driving automation systems: An informative HMI, including meaningful system names and responsibility-focused textual reminders, versus a non-informative HMI. Participants then answered questions regarding their responsibilities and permitted behaviors when using the different systems. Overall, results show that participants in the informative HMI group gave significantly more correct answers about their user role and behavioral possibilities than participants in the non-informative HMI group. The informative HMI also supported participants in correctly ordering systems by automation level. The findings of this study are used in an upcoming on-road study to examine a novel assessment method for mode awareness. Future research could further examine users’ role-related information needs and the most effective ways to convey this information via the HMI.

Keywords: Sustained Driving Automation, Human-Machine-Interface, Human-Machine-Interaction, User Role

DOI: 10.54941/ahfe1007022