> If every car on the road was synced then they could drive more closely to each other and at much faster speeds. This would optimize road space, decrease congestion, and reduce transit times.
Fair enough. But keep in mind cars only solve this last mile problem when there's high throughput roads connecting all possible trip starts / destinations. In American we have this infrastructure (at a great cost in city design and tax payers dollars), but cities in many other countries don't have this and don't want it either.
So like a train?