Although increasing the speed has entailed many technical and operational changes, HSR still fulfils the same quantitative and qualitative requirements as classical rail:

• Ability to accommodate various contexts and cultures,
• Capacity,
• Interoperability,
• Reliability,
• Safety and security,
• Sustainability.

This evolution has also made it possible to benefit from many other innovations beyond those simply enabling higher speeds, as there is no point improving one aspect of a journey chain (travel time) if the other links in the chain remain weak.

In addition, a thorough review of all the interfaces between the system components and of all the operating and maintenance procedures is necessary, as time gained for the passenger by the increased speed can be cancelled out by an unacceptably high ticket price.