Is this formally quantified, e.g., in an amount of time the human must be able to take control within? If that amount of time is like 5 seconds or longer, and t

Is this formally quantified, e.g., in an amount of time the human must be able to take control within? If that amount of time is like 5 seconds or longer, and the system is empirically demonstrated to maintain safety so long as the human is always ready take over in 5 seconds, that would be very compelling.