How is a change like this going to be implemented? E.g. are they going to mainly update some tracks everywhere (and have two systems running in parallel), or all tracks in selected areas (and have passengers change), or something else?
Was there a comparable large scale rail infrastructure change in some other country?
Baltic states attempted this (project Rail Baltica). Lots of EU money were spent with no visible result. I guess, several people in Baltic states became super rich, but in terms of rail infrastructure nothing was done.
I imagine you’re looking for the subheadings titled “completed in 2015” and “construction (2017-present)” though.
Yes, I understand very well that "research" is a pipe, where you put billions of euros in one end, and get stack of papers on the other end. And somebody becomes rich in the process. Sapienti sat.
It's worth noting that the non-HS standard gauge (part of Rail Baltica I) between Poland and Lithuania (up to Šeštokai Intermodal Terminal) was completed back in 2015. The freight trains have been operating on this line all the time.