Looking at "Driver Style Recognition" on google scholar seems to return some results including a few GM patents. The papers appear to mostly focus on accelerome

Looking at "Driver Style Recognition" on google scholar seems to return some results including a few GM patents. The papers appear to mostly focus on accelerometer data over longer periods of time, so they don't seem to be directly relevant to labeling the behavior of other nearby cars. There might however be some newer extensions of the work which could be more relevant to self driving cars, though it wouldn't be unsurprising if it was not published information.