Looking back over the past 40 years of railway history at ATP (automatic train protection)/ATC (automatic train control) systems across Europe, it is easy to appreciate the need for a common harmonised, interoperable train control system. Most countries currently have their own proprietary ATP/ATC system (see Fig. 1).
Even where the basic systems are very similar, the functionalities are usually different – resulting in incompatible, non-interoperable systems. This is a major hindrance to trans-European cross-border traffic.
In view of this situation, the railways, in collaboration with industry, specified the European Train Control System (ETCS) as a means of ensuring optimum operational and economic efficiency across the Continent.
These efforts subsequently led to a series of System Requirement Specifications, which have now
reached Version 2.2.2 (the so-called Class 1 functionality for interoperability).
In April 2000 in Madrid the railways and industry (united in the UNISIG group) agreed to freeze SRS 2.0.0 for a minimum period of 18 months in order to provide stable specifications for the first commercial projects, such as the Madrid-Lerida high-speed line (HSL) in Spain, the Rome-Naples line in Italy and HSL South in the Netherlands.