It should be noted that there are currently no published research studies that show any positive or favorable evaluation regarding human driver re-engagement.
Past studies in fact show the opposite. For example, takeover reaction times among individual drivers were shown to be anywhere from two seconds to almost half a minute.
Clearly half a minute is too long beyond reasonable times of re-engagement. So all is lost?
As part of the California DMV Disengagement Reports the driver time to takeover time measurement must be included. A cursory examination shows reaction times on the order of seconds. It’s a positive sign that takeover time is a measurement and hopefully with time this will receive the proper attention and improvements.