  The central points of communication network flow has often been identified
using graph theoretical centrality measures. In real networks, the state of
traffic density arises from an interplay between the dynamics of the flow and
the underlying network structure. In this work we investigate the relationship
between centrality measures and the density of traffic for some simple particle
hopping models on networks with emerging scale-free degree distributions. We
also study how the speed of the dynamics are affected by the underlying network
structure. Among other conclusions, we find that, even at low traffic
densities, the dynamical measure of traffic density (the occupation ratio) has
a non-trivial dependence on the static centrality (quantified by "betweenness
centrality"), which non-central vertices getting a comparatively large portion
of the traffic.
