I had heard that the Tesla Model S (the luxury electric car) had a giant touch screen as one of the main interfaces for secondary car functions and always wondered what that might be like from a human factors/usability perspective. Physical knobs and switches, unlike interface widgets, give a tactile sensation and do not change location on the dashboard.
This post is an interesting examination of the unique dashboard:
Think about a car’s dashboard for a second. It’s populated with analog controls: dials, knobs, and levers, all of which control some car subsystem such as temperature, audio, or navigation. These analog dials, while old, have two features: tactility and physical analogy. Respectively, this means you can feel for a control, and you have an intuition for how the control’s mechanical action affects your car (eg: counterclockwise on AC increases temperature). These small functions provide a very, very important feature: they allow the driver to keep his or her eyes on the road.
Except for a the privileged few that have extraordinary kinesthetic sense of where our hands are, the Model S’s control scheme is an accident waiting to happen. Hell, most of us can barely type with two hands on an iPhone. Now a Model S driver has to manage all car subsystems on a touchscreen with one hand while driving.
The solution, however, is may not be heads-up displays or augmented reality, as the author suggests (citing the HUD in the BMW).
While those displays allow the eye to remain on the road it’s always in the way–a persistent distraction. Also, paying attention to the HUD means your attention will not be on the road–and what doesn’t get paid attention to doesn’t exist: