Visual search tasks

This study investigated the differences between head-up display (HUD) and head-down display (HDD) systems in vehicles with the ultimate goal of increasing driver performance and safety. Our initial focus was on comparing drivers' visual task performance (and associated driving behavior) while using a HUD and HDD. In a medium-fidelity driving simulator, 16 experienced drivers performed two types of tasks, a structured (text) and a semi-structured (grid) visual search task while driving. They first completed a baseline drive using a driving simulator with no secondary tasks followed by four drives under various conditions: HUD-Text, HUD-Grid, HDD-Text, and HDD-Grid. The study returned mixed results. HUDs generally contributed to more secondary task errors, but overall, users still preferred to use HUDs over HDDs. The response time to complete tasks was unevenly affected by display type. While there was no difference between response times in the grid tasks (HDD vs. HUD), the HUD was associated with significantly faster task performance as compared to the text tasks. These results suggest that HUDs may offer advantages to drivers in some task scenarios but more research is needed to understand under what conditions they do not add value.