Resumen
With increase of the speed limits of the TGV train systems, there are many problems arising as regards the design, used materials and safety. Solutions to these problems demand heavy investments from the SNCF company into research and development projects. As such investments must be profitable in a longer term, new TGV lines have to be established between places where there is a sufficient need for long distance travel able to bring reasonable profit to the TGV train system operator.