It seems that very few Frecce/Italo trains use the direct connection from Tiburtina to Rome-Naples HSR. What are the reasons? Low demand for through traffic? Is Tiburtina so far off for travellers with destination Rome?

Great insights. Similar discussions on various projects in Germany about which traffic new tracks should serve. And different outcome m depending on location: new line Offenburg-Freiburg will be freight exclusive, Frankfurt-Mannheim mainly HSR during the day.

Some more pictures showing the southern entrances. Access to the station will vastly improve. Historic "Bonatzbau" being modernised similar to Leipzig Hbf and will host several shops and food options

Great work! Proper city access is the biggest out of many flaws of German HSR lines. Frankfurt and Cologne are certainly the worst bottlenecks at central nodes of the network. Frankfurt Cross-city tunnel will help, but its price tag and timeline proves the challenges you outlined in your thread.

Will it be operated as a separate line or as a brach of Tuen Ma line?

Had the opportunity to use the KTT back in 2013 from Guangzhou East to Hung Hom Station. First Class upper deck. Great train. Convinced it would find its customers today, maybe with additional stops? But it would be difficult to find paths on the crowded East Rail Line.