But that
would be alpha and beta testing on the road.
How can something be tested elsewhere if,
minutes after Car A learns something (Learnt Lesson L) in London (based on Incident X), Car B is putting it into practice in Miami? Where is the off-road testing? There isn't any. There's no involvement in the creation of the solution (that which is learnt and then passed onto other cars) by anything other than Car A.
There is no guarantee that the solution does not cause problems, either in a replay of Incident X or incidents that resemble Incident X. And if the solution is a variation on "I wouldn't start from here", it may involve doing something else in the run up to Incident X that avoids Incident X entirely... but then has other cars changing their behaviour in situations that resemble the run-up to Incident X that would not have ever led to a replay of Incident X, but might lead to another incident.
Now if that sounds complicated, just imagine what lesson learning means, both for the cars learning them and to those changing their decision trees based on that learning.
And then there is the issue that laws (or even the side of the road on which the cars drive) are not identical in different countries. Such things mean that the lessons learnt have to be transformed so that they take account of the different driving environments found around the world.
So the list of areas where problems might occur is legion: incorrect analysis of Incident X; incorrect determination of the solution; incorrect creation of the solution for Car A's decision tree; incorrect transformation of Car A's decision tree changes to match the driving environment experienced by Car B in Miami. And in all of this, there is no independent stress testing of the solution in Car A or Car B (or the hundreds of millions of other cars that are given the solution)... unless you count the stress of passengers in those cars that suddenly start performing strange, not to say inappropriate to the conditions, actions all over the world.
The only safe place to be might be behind vehicle-proof walls.... (And did you see those huge autonomous mining trucks in that episode of Click...?
)