The second principle Lathrop calls the coffee-spilling principle: For us not to get surprised, then freaked out by a driverless car, we need to know what it is going to do before it’s actually done. Third, and perhaps most vital in fostering trust, is that we need to know what the car is seeing. And finally—the “plus one” in Lathrop’s formulation, because it relates not just to the user but to the interaction between user and machine—we need perfectly clear transitions when a car takes control, or when we take control from a car.
