European railways move 1.4 billion tonnes of freight and 4.2 billion passengers annually. Behind these numbers lies a complex engineering challenge: making trains from different manufacturers, running different software, communicate seamlessly with trackside equipment across national borders.
Railway interoperability is the ability of trains to operate safely and continuously across different networks while maintaining required performance levels. Without it, cross-border rail transport would grind to a halt at every country or technical border (e.g. switch between lines equipped by different suppliers).
Technical Specifications for Interoperability (TSI) define interoperability as:
Interoperability means the ability to allow the safe and uninterrupted movement of trains that accomplish the specified levels of performance.
The European Train Control System (ETCS) was designed to solve this problem. Unlike national signaling systems, which evolved independently in each country, ETCS provides a standardized framework. Every manufacturer follows identical specifications, ensuring that a train built by supplier A can operate on tracks equipped by supplier B—regardless of which country either operates in.
THE PAYOFF FOR OPERATORS AND PASSENGERS
This standardization delivers concrete benefits. Infrastructure managers can source equipment competitively rather than being locked into single suppliers. Railway operators can deploy their fleets across multiple networks without costly hardware modifications. And passengers experience what they actually want: uninterrupted journeys that don’t require changing trains at borders.
The challenge lies in the transition period. Today’s European network is a combination of legacy national systems and modern ETCS installations. The Netherlands alone operates three different signaling technologies simultaneously: the national ATB system, ERTMS Level 1, and ERTMS Level 2. Trains running on Dutch tracks need equipment compatible with all three.
Technical Specifications for Interoperability (TSI) govern how this complex environment functions. These regulations ensure that on-board systems react predictably to trackside data, regardless of manufacturer. The specifications standardize everything from communication protocols to safety functions.
For stakeholders investing in rail infrastructure, interoperability isn’t optional—it’s the foundation that makes European rail transport economically viable and operationally practical.
