Abstract: A traffic coordinator is disclosed which utilizes a master unit and a plurality of secondary units wherein the secondary units are positioned at artery cross streets for controlling the main artery traffic in a coordinated fashion. Both the master unit and secondary units contain microprocessors for calculating parameters utilized in the coordination system. The coordination system may be installed in already existing timer-controlled intersections and serves to provide a highly efficient real time control of artery green bands, offsets and splits to achieve optimum traffic flow.