Interesting. I used to use VoiceOver when doing platelet apheresis (lying down in a bed for an hour and a half) and I found that a lot of stuff I wanted to do other than play/pause needed two hands to perform reliably, like making the rotor gestures. I'm having trouble imagining what's easier and safer to do with VoiceOver while driving compared to glancing at the phone for a tenth of a second and then positioning your finger later based on what's on the screen.
VoiceOver is just better designed. I have a blind friend who never figured out how to use an Android device because of the radial menus. I had to explain to him exactly how to use them, because the way Android teaches it to users is by SHOWING A DIAGRAM ON THE SCREEN. Way to go, Google.
