The described vehicle traffic simulator is designed to facilitate analysis of traffic flow and to experiment with postulated traffic control systems. It offers users a large amount of flexibility in specifying network, intersection, vehicle, and control parameters. The logical flow of vehicles, as well as much of the control system, is preprogrammed. Vehicles varying in size may change lanes, turn, change velocity (including reaction and acceleration delays), and merge. Inputs may be varied, turns may be eliminated, and vehicles may be routed through the network. The user supplies the geometrical characteristics and input information unique to his particular network in data cards for the program.Some applications to real traffic networks (including a validation procedure) and some simple control experiments are discussed. The model, programmed in a special version of GPSS II and in FAP for the IBM 7090/94 systems, can be used in the simulation of single intersections, arterial routes, grid networks, and throughways.