[TaylorAlexander]

What I mean specifically is that competitors self driving systems use "HD maps" meaning they store the entire world in 3D and then they localize themselves to that world (at least, this is what Karpathy says competitors do). So those systems cannot navigate any stretch of road they haven't seen.

But with the Tesla, it is learning to drive in general. It does not need an HD map of a fork in the road to understand how to navigate it. Just as a person who learned to drive in California will have little trouble driving in Florida, a neural network that has learned to drive on a million intersections will be pretty good at navigating most intersections. Especially because the corner cases will stand out and become integrated in to training. So it may see many intersections, but it will generally know what to do with one even if it has never seen it before.

Though I would suspect that the competitors are perhaps using HD maps to jumpstart a system that long term would behave more like the Tesla one. Mapping every road is a lot to ask.