The Tesla warns you, what, 6 times before disabling autopilot. Why not have the car engage the emergency lights and gradually slow down for each warning - eventually coming to a full stop. This plays directly into human impatience, likely resulting in hands on the steering wheel after the first warning. In the event that the driver does not react there is probably something wrong (e.g. seizure) and the car should come to a complete stop for safety. This is a very real trolley scenario because a stopped car on the highway is asking to be rear-ended, but it's still far better than a car traveling at 60mph with an incapacitated driver.

My last idea on how to eliminate these types of casualties was met with fair criticism (TL;DR - battery ejection)[1]. Am I missing anything with this idea?

[1]: https://news.ycombinator.com/item?id=16720680