How to make large touch screens usable while driving

Large touch screens are recently appearing in the automotive market, yet their usability while driving is still controversial. Flat screens do not provide haptic guidance and thus require visual attention to locate interactive elements that are displayed. Thus, we need to think about new concepts to minimize the visual attention needed for interaction, to keep the driver's focus on the road and ensure safety. In this paper, we explore three different approaches. The first one is designed to make use of proprioception. The second approach incorporates physical handles to ease orientation on a large flat surface. In the third approach, directional touch gestures are applied. We describe the results of a comparative study that investigates the required visual attention as well as task performance and perceived usability, in comparison to a state-of-the-art multifunctional controller. We found that direct touch buttons provide the best results regarding task completion time, but with a size of about 6x8 cm, they were not yet large enough for blind interaction. Physical elements in and around the screen space were regarded useful to ease orientation. With touch gestures, participants were able to reduce visual attention to a lower level than with the remote controller. Considering our findings, we argue that there are ways to make large screens more appropriate for in-car usage and thus harness the advantages they provide in other aspects.