The important calculation then is how many different types of rare situations are encountered, what it means to be a rare situation, how often all rare situatio

The important calculation then is how many different types of rare situations are encountered, what it means to be a rare situation, how often all rare situations happen in total, and how much better or worse the human or computer does. When I hear about Uber’s cars having issues with the apparently rare situations of, say, street lanes being restriped in a different place, or with delivery vans parked partially in a lane, I realize that much city driving is a bunch of rare unusual situations strung together in a row that requires constant improvisation. Construction, wrecks, emergency vehicles, delivery vehicles, weather, power outages, traffic signals on the fritz, funeral processions, pedestrians, loose debris from other cars, blown tires in the lanes, faded lane lines, parking lots, traffic jams, farm vehicles, moving vans... I think we’re going to find out that an acceptable level of automated safety ends up making automated cars so poor at navigating around the real world that it’s going to be a commercial failure.