Shouldn't it be possible to train for these scenarios using imitation learning and expert demonstrations? For example, Tesla seems to save replays of when its vehicles would have behaved significantly differently compared to how the driver actually behaved, and this data is supposed to be quite useful.

Is this type of crowdsourced driving data a crucial part of achieving Level 4+ self-driving? If so, it seems that driving around the same six city blocks of SF or cruising down Central Expressway in MV is going to produce diminishing returns in terms of producing measurable progress.