A better solution for the problem is a device that the technology for already exists.
A phone signal scrambler that turns on when the vehicle is in motion. Scrambles signal, phone no worky!
Stop car and the signal returns. Problem resolved.
The reason they will not do this?
Money. The phone companies want the cash generated by texts and talk time.
MOst newer cars have bluetooth setups that allow hands free operation of the phone — both calls and text. MY Hyundai will allow me to text message through voice activated commands.
Signal scramblers are illegal and what about non-driving passengers?
A better solution would be to require all cars manufacturers to provide hands free integrated radio systems that facilitate calls but not texts.
Or voice to text messages, my phone already does this but then again why not just call the person? LOL!