As a kid, I got to drive trains a bit. Maybe the first thing you notice when you sit down is that there's no steering wheel, only a throttle. Trains've been automated increasingly for decades. Sometimes there's nobody in the yard anymore. Or, like, one guy with chestpack controls. All of which means the legal standard of "who had the last clear chance to avoid the accident" dissolves into a simple arithmetic equation of mass and velocity.
As in whoever has the most wins. Like it is with bike couriers and garbage trucks. Inevitably, when you do hit a cow, after you finish peeling it off the front of the engine, it's always tragic. The farmer'll tell you it's a crying shame because that particular cow had just won a gold medal at the state fair. Every time. Railroads pay, every single time. Seems like that's going to be one more factor in the cost of doing business around automated cars as well.
As policy develops, we'll have to make sure that the incentives aren't perverse. In China, when a driver hits a pedestrian the rule is to back up and run them over a few times to be sure they're dead, because the penalties for a kill are so much less than if the pedestrian survives. Let's hope that kind of calculation isn't rolled up into the AI.