Visual Enhancements for the Driver's Information Search on Automotive Head-up Display

In the past, in-vehicle head-up displays (HUDs) were used to display simple information including driving speed and the distance between cars. However, recent HUDs now display complex information such as advanced driver assistance information. This study aims to identify the effects of visual enhancements for HUDs on the driver's performance and workload. Twenty participants conducted the tracking tasks for information search while driving in an automotive simulator environment. The participants experienced three levels of visual enhancements (none, shaded reference bar, translucent reference bar) for each task difficulty (low, medium, high). The results showed that visual enhancements and task difficulties had a significant effect on the tracking errors and subjective workloads. These findings verify that the translucent reference bar significantly improved the tracking performance. Furthermore, the visual enhancement cues on the HUDs play an important role in visual search. This research provides practical guidelines to ensure road safety through minimizing cognitive workload on drivers. Therefore, the results will encourage interface designers to consider the visual enhancement for HUDs from a user-centered perspective.