01487nas a2200133   4500008004100000245011100041210006900152300001200221490000700233520101500240100002301255700002701278856004801305       2012                        eng d00aAdaptive self-organization vs. static optimization: A qualitative comparison in traffic light coordination0 aAdaptive selforganization vs static optimization A qualitative c  a386-4030 v413 aUsing a recently proposed model of city traffic based on elementary cellular automata, we compare qualitatively two methods for coordinating traffic lights: a \emph{green-wave} method that tries to optimize phases according to expected flows and a \emph{self-organizing} method that adapts to the current traffic conditions. The \emph{self-organizing} method delivers considerable improvements over the \emph{green-wave} method. Seven dynamical regimes and six phase transitions are identified and analyzed for the \emph{self-organizing} method. For low densities, the \emph{self-organizing} method promotes the formation and coordination of platoons that flow freely in four directions, i.e.\ with a maximum velocity and no stops. For medium densities, the method allows a constant usage of the intersections, exploiting their maximum flux capacity. For high densities, the method prevents gridlocks and promotes the formation and coordination of ``free-spaces" that flow in the opposite direction of traffic.1 aGershenson, Carlos1 aRosenblueth, David, A.  uhttp://dx.doi.org/10.1108/03684921211229479