This paper describes a model which, by applying the kinematic wave theory, draws the trajectories of shock waves propagating from link to link of coordinated traffic signal systems. A BASIC program is developed to draw the trajectories on the time-space diagrams on the personal computer display in turn under arbitrary street, traffic and signal conditions. Using this model, the delay in each link and inflow traffic from main and cross streets at each intersection can easily be calculated. This paper expands the model by Michalopoulos et al., which target is confined to a single signalized link, so as to be able to apply to arterial streets made up of a given number of links.