They can probably extend this system (judging purely by the analogy since I am not a network guy) to their self driving cars one day. One would think that a similar mechanism would be needed to manage traffic.
Furthermore, traffic controller(s) would constantly gather information about traffic conditions from each intersection, and tell them how to direct the traffic to optimise road usage.
This way, the traffic controller knows everything about the optimal way traffic should flow, and it only has to make decisions based on the number of intersections rather than the number of cars. If you consider that one intersection could have tens of thousands of cars per day, that provides a huge saving in computation.
This differs from the analogy in the article; Intersection = Router, Car = Packet.