MIT Professor Emeritus of Robotic Rodney Brooks has published a thought-provoking essay on the most concrete, most likely ethical questions that will be raised by self-driving cars; Brooks is uninterested in contrived questions like the "Trolley Problem" (as am I, but for different reasons); he's more attuned to the immediate problems that could be created by selfish self-drivers who use their cars to get an edge over the people who drive themselves, and pedestrians.

(1) People will jump out of their car at a Starbucks to run in and pick up their order knowingly leaving it not in a legal parking spot, perhaps blocking others, but knowing that it will take care of getting out of the way if some other car needs to move or get by. That will be fine in the case there is no such need, but in the case of need it will slow everything down just a little. And perhaps the owner will be able to set the tolerance on how uncomfortable things have to get before the car moves. Expect to see lots of annoyed people. And before long grocery store parking lots, especially in a storm, will just be a sea of cars improperly parked waiting for their owners.

(2) This is one for the two (autonomous) car family. Suppose someone is going to an event in the evening and there is not much parking nearby. And suppose autonomous cars are now always prowling neighborhoods waiting for their owners to summon them, so it takes a while for any particular car to get through the traffic to the pick up location. Then the two car family may resort to a new trick so that they don't have to wait quite so long as others for their cars to get to the front door pick up at the conclusion of the big social event. They send one of their cars earlier in the day to find the closest parking spot that it can, and it settles in for a long wait. They use their second car to drop them at the event and send it home immediately. When the event is over their first autonomous car is right there waiting for them–the cost to the commons was a parking spot occupied all day by one of their cars.

(3) In various suburban schools that my kids went to when they were young there was a pick up ritual, which I see being repeated today when I drive past a school at the right time. Mothers, mostly, would turn up in their cars just before dismissal time and line up in the order that they arrived with the line backing out beyond the school boundary often. When school was over the teachers would come outside with all the kids and the cars would pull up to the pick up point^{\big 4}, the parents and teachers would cooperate to get the kids into their car seats, and off would go the cars with the kids, one at a time. When the first few families have fully driverless cars, one can imagine them sending their cars to wait in line first, so that their kids get picked up first and brought home. Not only does that mean that other parents would have to invest more of their personal time waiting in order to get their kids earlier, while the self driving car owners do not, but it ends up putting more responsibility on the teachers. Expect to see push back on this practice from the schools. But people will still try it.

Early on in the transition to driverless cars the 1% will have a whole new way to alienate the rest of the society. If you don't think so, take a drive south from San Francisco on 101 in the morning and see the Teslas speeding down the left most lane.