$230bn is one hell of a symbol. There would have to be an economic case for such a project and, non-specialist as I am, I just don't see it.
However I would note that this isn't coming out of the blue -- we've been hearing of Chinese proposals to make all roads lead to Beijing for a while now:
Remember how long ago when China started to build high speed railway lines it was a seen as a trememdous wast as there were hardly any Chinese with enough money to pay for a ticket.
Also the lines will pass quite a few towns like Urumqi, with three million inhabitants. When the lines are operating such towns are likely to grow significantly.
To integrate the economies of Asia and Europe large flows of people in all directions are necessary. Railways are to be preferred because they have large capacities, don't cause a lot of noise to people living around the stations in the way airports do and don't necessarily use fossil fuel. Aircraft fly at 900 km/h but you have add to your flying time hours on the airports on both ends as well as often hours getting to and from the airports.
The high speed line will preferrably be build at standard gage, 1435 mm, and be extended to Berlin and eventually Dublin.
Remember how, long ago, the French internal air passenger network was killed off by TGV. I suppose a considerable air passenger network will remain in Eurasia but it will be much smaller than otherwise necessary.
Neither would I. The four large cities in The Netherlands have between five hundred and eight hundred thousand inhabitants.I would not call Urumqi, the provincial capital of Xinjiang, a "town".
Precisely the point.
High Speed rail for Trans Continental journeys are the future as they electricity the trains use can come from all or any source in any mix, all of which will be vastly cheaper (and increasingly; more available) than aviation fuel.
Commercial air travel has not gotten any faster for the past 40 years. The main limiting factors are fuel price and safety. HSR offers a viable alternative. It is not much slower than planes even over medium distances, when we take into account how much time we spend waiting and getting to and from the airport. In addition, HSR offers a more enjoyable trip and better versatility.
As technology improves, HSR will become even faster.
True, but HSR is more in line for passengers. I don't know about cargo and commercial use for it.