European Rail Traffic Management System in Great Britain
The European Rail Traffic Management System (ERTMS) is an initiative backed by the European Union to enhance cross-border interoperability and the procurement of signalling equipment by creating a single Europe-wide standard for train control and command systems.
Its main components are the European Train Control System (ETCS) and the GSM-R communications system. ETCS is a standard for track-train radio communications using balises (Eurobalises) and associated in-cab train control, while GSM-R is the GSM mobile communications standard for railway operations. ERTMS can operate at different levels depending on specific local requirements. Under ERTMS speeds are displayed in the driver's cab in km/h and at Level 2, lineside speed indicators are optional.