5. Conclusion

Today's railway interoperability is the result of a long development that began in the early days of the railroads; even though railway interoperability was initially born as a concept limited to a single mode of transport, focusing rather on purely physical interfaces (Berne rectangle, gauge), over the years it has integrated other dimensions, covering energy, signalling, data exchange and multimodality, for example.

This evolution is in full swing and will continue to develop in the years to come; however, its evolution may take different paths, as it will be necessary to find the right balance to reconcile complementary or opposing requirements between the two poles "control/tutelage" and "freedom/creativity", such as :

• standardization/innovation ;

• uniform standard solutions/diversity...