‘a specific type of flow diagram, in which the width of the arrows is shown proportionally to the flow quantity. Sankey diagrams put a visual emphasis on the major transfers or flows within a system. They are helpful in locating dominant contributions to an overall flow. Often, Sankey diagrams show conserved quantities within defined system boundaries. [….] One of the most famous Sankey diagrams is Charles Minard’s Map of Napoleon’s Russian Campaign of 1812. It is a flow map, overlaying a Sankey diagram onto a geographical map.’
The most important thing to understand is that not all miles are the same. Most miles that we drive are very easy, and we can drive them while daydreaming or thinking about something else or having a conversation. But some miles are really, really hard, and so it’s those difficult miles that we should be looking at: How often do those show up, and can you ensure on a given route that the car will actually be able to handle the whole route without any problem at all? Level 5 autonomy says all miles will be handled by the car in an autonomous mode without any need for human intervention at all, ever. So if we’re talking to a company that says, “We can do full autonomy in this pre-mapped area and we’ve mapped almost every area,” that’s not Level 5. That’s Level 4. And I wouldn’t even stop there: I would ask, “Is that at all times of the day, is it in all weather, is it in all traffic?” And then what you’ll usually find is a little bit of hedging on that too. The trouble with this Level 4 thing, or the “full autonomy” phrase, is that it covers a very wide spectrum of possible competencies. It covers “my car can run fully autonomously in a dedicated lane that has no other traffic,” which isn’t very different from a train on a set of rails, to “I can drive in Rome in the middle of the worst traffic they ever have there, while it’s raining,” which is quite hard. Because the “full autonomy” phrase can mean such a wide range of things, you really have to ask the question, “What do you really mean, what are the actual circumstances?” And usually you’ll find that it’s geofenced for area, it may be restricted by how much traffic it can handle, for the weather, the time of day, things like that. So that’s the elaboration of why we’re not even close.