> how quickly might it react to a perceived obstacle? Very quickly, you have a split second to avoid whatever it decides to steer towards. The problem becomes

> how quickly might it react to a perceived obstacle? Very quickly, you have a split second to avoid whatever it decides to steer towards. The problem becomes even worse after you factor in that autopilot only works in easy to drive conditions (i.e. highways with high speeds). To make things even worse, you get less attentive when you are passive for a long period. I.e. if the autopilot fails in your first 20 seconds of driving you may very well be able to react, but if it has been driving perfectly for 20 minutes, you're probably already lulled into a passive state, and way to slow to react.