What Network Structure Provides the Smoothest Flow?

From a paper by Zoltan Toroczkai, Balazs Kozma, Kevin E. Bassler, N.W. Hengartner, and G. Korniss:

If the flow received by a node has to be processed, it will happen at a finite rate. For example, a node receiving a packet, has to read off its destination and find out to which neighbor to send it. This is a physical process and takes a non-zero amount of time. Thus, if a node receives too many packets per unit time, they will form a queue, and long queues will generally cause delays in information transmission and thus leads to congestion, or jamming. An important question then arises: Can the topology of the underlying substrate graph influence the level of congestion in the network?

The answer is yes...

See also the wiki summary.