I used to hear people say they couldn't drive without the radio because they "needed the distraction". I never got that. Isn't driving supposed to be the only thing you're doing while driving?
All the hands free apps in the world can't solve split focus. Even a bluetooth, voice activated system requires you to commit brain cycles to the conversation that's coming through that will take away from your ability to drive.
We sit and argue about how bad context switching is, how important it is in our careers as developers to focus on what we're doing, then we build apps and devices that are competing to be the best attention stealing devices they can be.