It seems like it's not ill-defined, it's like all categorization schemes. It's suitable for some purposes and not others. The level system is important to the e

It seems like it's not ill-defined, it's like all categorization schemes. It's suitable for some purposes and not others. The level system is important to the experience of the passenger, and to a number of design elements of the car, and, I would guess, to regulation. It's just not a total order on the capabilities or impressiveness of a self driving car project.