Indeed, perhaps the most startling conclusion of the study is that no one design — voice control, touchscreens or computer-like mouse and buttons — is universally superior....

There are even more useful conclusions we can infer from the AAA study. First is that allowing navigation destination entry while driving should be verboten... Second, complex tasks, no matter how many times practiced, do not become substantially less distracting with repetition. Automakers — and they are many — who justify their systems’ complexity by relying on familiarity are plainly full of bull patooties.

The last is that the success of any infotainment seems less driven by the hardware chosen — i.e. voice controls, touchscreens, etc. — than the quality of the software controlling it. While the report does find some specific infotainment systems better than others, the one glaring conclusion is that the perfect combination of non-distracting visual cues, easily manipulated manual tasks and low cognitive load audio commands does not yet exist. More importantly, such a perfect combination might never exist. source