  We present a novel mechanism to avoid congestion in complex networks based on
local knowledge of traffic conditions and the ability of routers to
self-coordinate their dynamical behavior. In particular, routers make use of
local information about traffic conditions to either reject or accept
information packets from their neighbors. We show that when nodes are only
aware of their own congestion state they self-organize into a hierarchical
configuration that delays remarkably the onset of congestion although, leading
to a sharp first-order like congestion transition. We also consider the case
when nodes are aware of the congestion state of their neighbors. In this case,
we show that empathy between nodes is strongly beneficial to the overall
performance of the system and it is possible to achieve larger values for the
critical load together with a smooth, second-order like, transition. Finally,
we show how local empathy minimize the impact of congestion as much as global
minimization. Therefore, here we present an outstanding example of how local
dynamical rules can optimize the system's functioning up to the levels reached
using global knowledge.
