Like Windows Genuine Advantage which is a tool to disable Microsoft Windows, Drive Assist disables your phone.

If it is based on detecting your location changing then presumably your phone can still ring or message when you stop at traffic lights. Instead perhaps it should operate against the ignition switch - or whatever alternative-power cars use instead of that.

It's called "voice mail". If I don't answer after four rings, it picks up automatically, plays a prerecorded explanation, and lets the caller leave a message for me.

Amazing modern technology.