From my experience with auto pilot, it doesn't look very far ahead, perhaps 5 meters. If you're at an intersection, particularly a larger one it tries to extrapolate where the 'lanes' are to cross the intersection but doesn't do a good job of looking to the other side and extrapolating back. In these situations the computer will essentially shut down and say it can't proceed. It's a little annoying, but if the algorithm isn't confident this is exactly what you want it to do.