  We analyze the effects of agents' decisions on the creation of congestion on
a centralized network with ring-and-hub topology. We show that there are two
classes of agents each displaying a distinct set of behaviours. The dynamics of
the system are driven by an interplay between the formation of, and transition
between, unique stable states that arise as the network is varied. We show how
the flow of objects across the network can be understood in terms of the
ordering and allocation of strategies. Our results show that the existence of
congestion in a network is a dynamic process that is as much dependent on the
agents' decisions as it is on the structure of the network itself.
