Continuous Visual Feedback of Risk for Haptic Lateral Assistance

Lateral assistance systems are a significant part of the currently existing Advanced Driving Assistance System (ADAS). In most cases, such systems provide intermittent audio and haptic feedback rather than continuous feedback, making it difficult for drivers to form a clear mental model. In this paper, we propose continuous visual feedback for the lateral assistance system by leveraging the Head-Up Display (HUD) alongside haptic feedback through the steering wheel. The HUD provides visualization of the risk profile underlying the haptic feedback. We hypothesize that our proposed visualization helps form a clear mental model and improves the system's acceptance. We conduct a user study on a simulated version of a car driving on a two-lane freeway and compare the haptic lateral assistance system with and without the visualization on the HUD. While both conditions received high acceptance scores, there was no significant gain or deterioration in acceptance between them. We discuss potential improvements in the visualization based on anticipation performance and qualitative feedback from users.