2022 Model Y with regular Autopilot. Phantom braking is rarely an issue
on divided highways; however, it's definitely an issue on highways without generous medians. If a semi is coming the other direction (especially over a hill) it will panic and slam on the brakes more than half the time (this has been the case since we bought the car in November). I've also had problems with the shadows cast by bridges and adjacent buildings as well as changes in road surface (e.g., the boundary between a section of road that was recently resurfaced to an older section of road). Further still, the problems seem to be worse in dim light or at night (it also insists on running the brights even when they're not necessary for a human, and even if it means blinding oncoming traffic) where it will occasionally phantom brake even on an empty divided highway. Moreover, sometimes it decides to abruptly drop the cruise control set point speed from 75mph to 40mph (even though it knows the speed limit is 70mph) which results in abrupt deceleration (not sure if this is the same as phantom braking or not).
Additionally, if you interrupt a phantom brake by manually accelerating, it often won't resume speed until it has decelerated to whatever it thinks its "safe speed" was at the time of the perceived danger, even if the perceived danger is well-past. So if you were going 60mph when it got spooked by a shadow and manually compensated for the phantom braking, when you let off the accelerator the car will still slow down to ~30mph even if you're a quarter mile past the shadow.
This is all frustrating, but the most frustrating thing is that I don't even know for sure what the car's reasoning process is--why does it sometimes sporadically set the speed to 30mph below the speed limit on a busy highway? What threat is it perceiving when it phantom brakes?
> and more often brakes hard and late ... If you have the minimum distance set to 2 or 3 car lengths, you should not be complaining about late and hard braking- that's the setting you chose.
I disagree here. As a human driver, I can prefer to follow someone "closely" (pretty sure I could fit 3 or 4 cars into Tesla's "2 car lengths"), but that doesn't mean I wait until I'm that far from them before I begin decelerating. There's no reason fundamental reason Autopilot can't do the same.
> It also is annoying slow to recover back to cruise speed from a slow down.
Fully agree. I think this pisses people off behind me more than the brake checking.
> The phantom braking is annoying but infrequent
I suspect this depends on what share of your driving is on divided versus two-lane highways.