Can in-vehicle touchscreens be operated with zero visual demand? An exploratory driving simulator study

There has been a rapid increase in the use of in-vehicle touch screens over the last decade, particularly for infotainment functions. However, one of the main concerns in the use of in-vehicle touchscreens whilst driving is visual distraction. Previous work has focused on extreme distraction for touchscreens (many/long glances away from the road). Here, we are motivated to understand how touchscreens can be designed to potentially be used with no off-road glances at all. An exploratory study conducted within a right-hand drive medium-fidelity driving simulator aimed to investigate whether certain combinations of button size, location and contrast for touchscreen menu buttons could be used with zero visual demand. Twenty-four participants drove along a UK motorway, were presented with one button at a time on a touchscreen located within the centre console and were asked to press the button as quickly and as accurately as possible using their left hand. The highest visual demand (mean 1.02 glances/task) arose for the smallest buttons (2x2cm) whereas the lowest visual demand (mean 0.52 glances/task) was associated with the largest buttons (14x14cm). Location and contrast had little effect on results. Therefore, it is concluded that zero visual demand can arise in nearly 50% of occurrences with very large (>14cm width) single press buttons.