According to the ERRAC (European Rail Research Advisory Council) study, 'Light Rail and Metro Systems in Europe: Current market, Perspectives and research implication', there are 170 LRT networks and 36 metro networks in Western Europe. It is expected that the number of new LRT systems could expand by more than 50% over the next 20 years. For metros, the number of new systems is expected to be limited to around five, whereas 55% of existing metro networks are currently extending existing lines or planning new lines. Most of the existing metro systems will have their rolling and signalling equipment replaced over the next 20 years and/or transformed from driver to driverless operation. These figures are in line with the target of the ERRAC Railway Business Scenario 2020 and will be dwarfed by the number of new systems being put into operation in the rest of the world, which are being built using European norms and expertise. This could account for more than 50% of the production of the European rail industry over the same period.

Passenger trips are expected to grow by 40% over the next two decades, across all transport modes. ERRAC's vision is that the rail market share could double and that the rail market volume could increase by more than a 150% in passengers over current volumes. To meet this expectation - which means a reverse in the current trends of the last 20 years - it is of utmost importance to develop reliable, affordable, attractive and even more energy-efficient urban rail systems for use in European cities. This calls for innovative and interchangeable constituents and subsystems with common harmonised interfaces. This will reduce the cost of ownership as well as the operation and maintenance of rail installations. It is vital in view of the growing complexity of new IT based subsystems that new products are developed along common interchangeable modular principles.