Been using NOA allday errday - and had my first surprise with it this evening.
Currently on 42.3, driving with NOA on Mad Max setting, just sharing for the sake of sharing. Had to take over to prevent NOA from rear-ending someone. You can hear the alerts (forward collision warning), so the car certainly sensed an event yet NOA did not try to react.
Love the new functionality but was a nice reminder to stay attentive!
This is less about NavOnAP and more about the auto lane change and TACC in general. It does not react quickly enough when cars are changing lanes (that can mean your car or other cars). I think the emergency braking would have kicked in soon, but not enough to prevent the collision, only enough to slow you down a bit.
Something like this happens to me on probably ~70% of my commutes. I guess it depends on what the roads and traffic are like where you drive how often it happens, because for some people apparently this is a rare occurrence. Autopilot tries to murder me and everybody else on the road around me so regularly that I would never consider anything other than staying attentive.
Well, OK, that's not quite true -- when I take road trips and travel through less urban areas with wide, well-marked lanes and exits, gentle curves, and fewer cars driving like they're fleeing armageddon, AP does quite well and I can totally see being lulled into a false sense of security. But I know that it's still just biding its time, waiting for its moment to strike...
And actually I'm being too hard on AP -- TACC is a valuable safety feature even though it's not 100% reliable. I am convinced that it makes me much safer; it has certainly saved my butt a couple of times. Autosteer is not a safety-improving feature as far as I can tell; at best it would help out if you fell asleep or had a heart attack, otherwise I think it's probably decreasing safety by allowing people to pay less attention to the road. And NavOnAP so far for me has very much been a negative on safety.
Tesla should take note that TACC, the only feature I consider really safety-improving at this point, is also available on quite a few other makes of car, and it's really just as good on many of them. I wish Tesla would focus less on "self-driving" features and more on safety-improving, "guardian angel" type features. The blind spot monitor and the acceleration limiting (when object detected ahead) features are really the best safety features in V9, hands down. NavOnAP is a dangerous gimmick.