Researchers at Oxford University in the UK are studying networks of all kinds -- traffic, the Internet, supply chains, and even tumors -- to understand where bottlenecks occur and how to route around them. The problem in most cases apparently occurs when a network uses a hub-and-spoke model to connect to a center. When all routes head toward the center, they invariably become congested... no matter how many routes are available. So building more routes directly to the center is not necessarily the solution.
What does seem to help, though, is to create alternative, indirect routes to the center, and to stagger traffic. In the case of car traffic, entry ramps with time delays and tolls charged for entering city centers at peak times have proven to reduce congestion. The downside is that drivers have to plan their commutes a bit more carefully. But if the end result is less time sitting in traffic jams, few will complain.
Source: Technology Research Network