The Dynamic Research, Inc. (DRI) Driving Simulator and recent applications to the study of ITS concepts and devices are described. This research grade simulator features a computer generated graphics roadway scene with a 180 degree deg forward field of view, a 6 degree of freedom motion cueing platform, instrumented cabs, control loaders, sophisticated vehicle dynamics models, and data acquisition. The advantages and possible limitations of using a driving simulator for the study of ITS are discussed. Recent applications of this simulator to the study of ITS topics including a navigation system, a driver assistance system, and adaptive cruise control are described.