smartphone ML algorithm to prevent texting while driving

Hi, the recent google patent on ~"any and all ML algorithms on smartphones" gave me an idea for the texting while driving problem. I work in telecom and have thought about this problem. We can detect that the phone is in motion with GPS at the phone or radio strength information at the switching center that the towers connect to. The problem is, someone can be riding in a car and they still need to be able to text.

One difference between the scenario of a driver texting vs a passenger texting is that the driver is likely not typing as they normally do while not driving. In particular the timing information between keystrokes could be used to detect one-handed typing which is characteristic of texting while driving. The phone screen could then be made to go blank until the phone's GPS shows that it has stopped.