[teeray]

The problem is that many authentication mechanisms could create a dangerous skinner box for drivers that have decided to flout the laws and text anyway. If we have phone users prove they’re not driving by solving math puzzles or tapping a flashing square or something, you will have a driver that attempts to do that while driving. The same goes for doing something like putting an NFC pad in the passenger door. There will be SOME driver out there that will attempt to reach across the car while driving to unlock their phone.

Allowing passengers to use devices in any capacity makes it extremely difficult to build technological solutions to this.