To borrow the form of the GP comment, there is no particular reason a phone should allow itself to be used when its owner is driving a car. Creating some arra

To borrow the form of the GP comment, there is no particular reason a phone should allow itself to be used when its owner is driving a car. Creating some arrangement of sensors and systems that could lock the phones of drivers may not be straight forward and would require buy-in from both phone manufacturers and car manufacturers, but seems possible in principle. The car could scan the drivers' face, then interrogate nearby phones, asking them if the driver's face matches the phone's owner. The phone could then lock itself if it does. There would be technical and privacy hurdles to overcome, but nothing impossible.