Steps to Automobile Autonomy

Worthwhile classification of levels of autonomy.  How might these also be linked to risk assumption and intelligence?

Steps to Autonomy
  In Cars by Benedict Evans

The standard way to talk about autonomous cars, shown in this diagram, is to talk about levels. L1 is the cruise control in your father’s car. L2 adds some sensors, so it will try to slow down if the car in front does, and stay within the lane markings, but you still need to have your hands on or near the wheel. L3 will drive for you but you need to be ready to take over, Level 4 will drive for you in some situations but not others, and Level 5 doesn’t need a human driver ‘ever’ and doesn’t have a steering wheel. ....

This seems pretty straightforward, until you start thinking about how you might actually deploy this - and about the fact that some places are easier to drive in than others.
As we can already see with the early tests being done with prototype autonomous cars (with their need for a human ‘safety driver’, today these are are effectively L2 or at best L3), autonomy of any kind in one city is different to another - Phoenix is easier than San Francisco, which is easier than Naples or Moscow. This variability applies not just across different cities and countries but also in different parts of each urban landscape: freeways are easier than city centers, which might be easier or harder than suburbs. .... "