After 3 alerts, it’s off until you park. There are visual cues that precede the alert though and these do not count. I don’t recall how many there are and for how long, but you start by seeing a message asking to have your hands on the wheel, then a blue line at the top, them the line starts pulsing ,then you’ve got an audio alert that is the first strike. Three strikes during the same drive and you need to park before using autopilot again.