Hmmm, weird idea here, but maybe that's the answer then?
If self driving cars are terrible at coping with the chaos humans grit their teeth and deal with, maybe software for engineering cooperative bumper-to-bumper traffic jams involving clogs of slow-moving self driving cars, that reduce the road speeds to constant 20 MPH (the /constant/ part being important), and eliminate chaotic lane changing to near zero for the group, is one way to bootstrap self driving cars.
In other words, low-performance self driving cars might work fine, and since people can lounge about, and disengage from the guidance and navigation tasks, why not go slower?
Then, add swarming to the mix, such that cars going to the same place, all travel slowly in a single group.
It's against the law to obstruct traffic, or violate minimum speed requirements, so certain laws would need to change. For example, zero emission vehicles can idle indefinitely, and software-controlled vehicles can interface with an external control network, approved to operate in such ways, with points of contact at operations centers for resolving problems, technical or otherwise.
So change laws to permit idle electric vehicles (in more places and controlled, desginated places, not just anywhere), and permit large slow moving groups to occupy certain corridors, at certain times, when jammed traffic is a known quantity, that driverless systems aren't the cause of. Driverless networks can cut into a slice of the jam, and possibly improve outcomes for members only at first, and eventually boost efficiency within the jammed system by augmenting flow through expert participation.
