[nkoren]

> But would self driving increase volume that much?

Absolutely. Not even accounting for induced demand, you'll see ~30% more vehicle-miles due to empty-vehicle repositioning.

As you say, accelerations and decelerations can be synchronised, accidents reduced, and standing wave behaviours eliminated, all of which will indeed help traffic flow more efficiently. But this is not by any means enough to compensate for empty-vehicle redistribution, much less induced demand.

> And like those futuristic car intersection scenes where cars dont stop at lights but all go through an intersection from every direction reducing traffic back-ups.

That's only possible in environments where there are no pedestrians or cyclists -- eg., segregated motorways/freeways, which already have no intersection conflicts. At best it represents a space saving, not really a time saving.