A simulator is an information presentation and performance monitoring system made up of many factors designed to aid in the understanding of train-driving performance. The way train simulators are used within industry can influence the way they are perceived by drivers and therefore levels of engagement and motivation to perform. At the processing level, the performance measures collected in the simulator must be chosen very carefully to give a complete picture of the way in which performance is changing. Research typically requires a basic output format to allow data to be added to databases of multiple individuals for processing and analysis in different programs. At the processing level of the system, consideration for the most appropriate measures to provide a complete picture of performance is paramount. The inputs of the system are the demands of training, performance review and research. There are numerous technologies that can be employed to provide a fundamental indicator of physiological arousal.