Ask your car manufacturer which the driver is supposed to do:
1. Wait to see if the autopilot will react to a situation, and if it doesn't, then (belatedly) react yourself. (Which is probably too late.)
2. Keep alert and react as fast as you can, yourself, not presuming to trust the autopilot. (In which case, why enable the annoying thing? It's more of a hindrance.)
BTW, regarding this particular situation, if the car in front of you is blocking your view of a stopped vehicle, and suddenly swerves to avoid it at the last moment, then I figure autopilots and humans will be equally ineffective.