I can't recall properly where I read it, but some time ago there was an idea to have stop signals also in front of the car, so the pedestrians would know if the driver/car is stopping.

There are also pedestrians who can take into account if the car is turning (obviously by watching the turning lights).

A self-driving car should have some reactions to people around it, so people could also respond properly to its actions, or know its intentions. There was a comment about an empty electric car near the intersection, staying still, and people around it can't tell if the car is parked, waiting, etc.