If there's a person at an intersection directing traffic, it will be very hard to have the car itself communicate with them as easily as a human can. Edge cases like that is where AGI would be needed it seems.
Sure it's probably feasible for cars to handle hand signals in the happy path, but anything outside of that will be disastrous. How will the car understand and communicate with a person who doesn't use the standard signals, aside from having some level of intelligence?
Sometimes. Other times they confusingly gesticulate or just shout out things, or even give conflicting signals. Humans can interpret these without much effort but it's a hard AI problem.