led to a reduced number of different
interaction devices but requires the
driver to search through a range of
menus to find a desired function.
The driver now has to divide his or
her visual attention between the
primary driving task and a central
information display (CID), which
requires a lot of visual attention
and thus distracts from the primary
Of course, with the increasing
number of new driver-assistance
systems, such as lane-departure
warning or pedestrian-detection systems, one could argue that today’s
cars also have “eyes” on the road,
removing some visual load from the
driver. However, from a legal perspective, the driver is still responsible for any traffic accidents. The user
interface in the car should therefore
be designed in the best possible
way to prevent driver distraction
and thus potential accidents.
Haptic Feedback in
Multifunctional Car Systems
Usually there are three ways to
interact with multifunctional sys-
tems in the car:
• Buttons and additional controls
are arranged around or near the CID.
Some of these buttons are context
dependent; their meaning is shown
on the display next to the button.
• A multifunctional controller is
used to navigate hierarchical menu
structures, which are shown on a
• Virtual buttons must be
“pressed” directly on a touch-
enabled version of the screen.
There are also combinations of
these interaction concepts available
on the market.
Which haptic feedback do these
interaction concepts provide? In
the first case, a kind of haptic feed-
back is given by the control itself:
Even if the driver has to look for the
meaning of a context-dependent
button mounted around the screen,
the button lets the driver feel if
it has been pushed and therefore
communicates if a function has
been selected. When the driver
knows the meaning of a context-
dependent button, he or she can
even select it without looking.