# Adaptive self-organization vs. static optimization: A qualitative comparison in traffic light coordination

 Title Adaptive self-organization vs. static optimization: A qualitative comparison in traffic light coordination Publication Type Journal Article Year of Publication 2012 Authors Gershenson, C, Rosenblueth, DA Journal Kybernetes Volume 41 Pagination 386-403 Abstract Using 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. URL http://dx.doi.org/10.1108/03684921211229479 DOI 10.1108/03684921211229479