When humans and robots take turns driving

Until recently, there was no question about who's responsible for an automobile's operation: the driver. Going forward, as driverless cars hit the roads en masse, that distinction will fade. When the robot cars get here, you'll be able to eat, text and sleep, but you won't drive, because there won't be a steering wheel or brake pedal. Your only role: Order the car where to go. Yet there's a lot of ground between the old-school cars that people are used to and the driverless experience promised in the next few years.