Well, first, it's not like driving while distracted is a new thing. People have been eating while driving, yelling at their kids while driving, drinking coffee, looking at maps, etc, since there have been cars. The problem is nothing at all to do with modern technology, and tech probably isn't even making it worse (anyone who can't manage talking on the phone and driving at the same time is too dumb to be on the road anyway, and would have crashed for some reason or another even without the phone).

The problem is that people don't pay attention to driving.

On top of that, everyone will just override it, making the device useless. People will already call you at any hour of the day, and even sit there on the line yapping incessantly when they KNOW you're on the road. People will punch the override and wonder why you have a message saying you're driving on your cellphone. We're a race of rude idiots, after all. And if you think your BOSS is going to wait (for anything, an emergency or just a random idiotic phonecall) just because his call brings a minor danger to your life? Yeah, right.

How can they tell your not a passenger?

@enome
it can't, it will block calls all the same.

I suppose that someone has decided that cell phones are only meant for walkers and despite having every phone maker out there now scrambling for GPS inclusion in their phones, we should also disable that feature when driving into unfamiliar territories. Hey, let's get rid of that music/cd playing thing too,while we're at it. In fact, let's just strap our arms to the steering wheel and duct tape ourselves to the seat. Once we restrict all movement that does not include driving, maybe we'll keep people from getting distracted behind the wheel. Unless, of course, someone drives while drunk or sleepy. I Know! We'll wire the seat with electrodes just in case your head bobs once too often. Finally, a safe and enjoyable car ride!