In order for self driving cars to really take off, all cars would need to be self driving. That would solve many problems at once.
Essentially, the cars would all be nodes in a single network. At all times they would be cooperating with one another, acting as coordinated cells within a single organism.
Perhaps the only way this could get started would be if some enterprising corporation made it happen. They would need to offer a fleet of vehicles to an entire municipality, completely replacing traditional automobiles.
I wonder whether anybody will actually do this.