The results of combining and evaluating driver/vehicle response and performance data from recent experimental studies are discussed and illustrated. Open- and closed-loop data are used to infer the behavior of drivers in various driving tasks and to determine the manner in which vehicle factors influence this behavior. Procedures are presented for establishing and predicting satisfactory or unsatisfactory vehicle performirnce regions and limits germane to driver/vehicle dynamic performance. Implications from the data are used to tentatively identify safety-relevant vehicle performance characteristics, requirements, and criteria to provide guidance for future test programs.