E.R.T.M.S. ( European Rail Traffic Management System/European Train Control System ) it is a system for managing and controlling the train and railway traffic designed to interoperate in several European countries. A convoy equipped with Ertms is able to move from one country to another on lines equipped with this technology, already widely adopted by many states and on high-speed lines. On the dashboard of the ERTMS-equipped car, a series of information is displayed to help the driver of the train. It is no longer necessary for the driver to visualize the signal outside the vehicle, long before it the driver will know where he is and what aspect he will assume the signal, so also for line voltage changes, speed changes, distances and situations of emergency. The on-board system, coordinated with the ground system and synchronized with a computer, is able to monitor every phase of the train's journey and of the infrastructure, reacting instantly to every variation of the conditions.