A good way to think about bottlenecks is to picture a highway traffic jam. The traffic jam usually
results from the fact that a large portion of the cars on the road must pass through a narrow
passageway. Another possible reason is that the stream from one highway merges with the
stream from another. In either case, the bottleneck is that portion of the road network having
the greatest proportion of cars per lane. Clearing the bottleneck entails locating it and then
adopting one of two strategies: