However, in a recent driving simulation study
that focused on touch target size for in-vehicle information
systems, the authors determined that a touch key size of at
least 17.5x17.5 mm minimizes navigation error rate, lane
deviations, driving speed variation and glance time while
maximizing subjective usability ratings
Recommended limitations are
as follows
•For touch devices without haptic feedback, limit
touch screen interactions to six touches for every
12 seconds.
•For touch devices with haptic feedback, limit
touch screen interactions only to certain functions.
•No restrictions apply to physical buttons while
driving.
•No restrictions apply while standing.
if system
responses take longer than 250 ms, the system should inform
the driver that it has recognized the input. If longer delays
(500 ms and above) are inevitable, Utesch and Vollrath [29]
recommend using acoustic or tactile feedback to indicate
system readiness, as this will reduce off-road glances.
Examples:
1. Demonstration of a 2015 Audi MMI System, showing
constant and short system response times [31].
2. Demonstration of a BMW 5 Series iDrive, showing long
but constant delays [32].
3. Demonstration of an Apple CarPlay IVIS in the Ferrari
FF showing long and variable delays. This might cause
distraction and annoyance [33]
Figure 9. VW Passat dashboard which combines few physical buttons with
a well-readable touch display LOL