Research in the field of railway construction

They may have to increase the cooling of the permafrost. I hope they use solar energy for this.

I will go ahead and assume you're saying hard geography is the main reaon railways are not built in some regions. Yes. Hard geography. Like, well, Transpolar Canada, just worse.
Permafrost, bogs, mighty rivers (and thousands of small creeks), winters that get as cold as −65°C, mountains, no or very few permanent settlements…check @ https://www.marketresearchfuture.com/categories/packaging-transport .There actually were projects of Transpolar Railway. The first one was drafted shortly before the WW1 — but obviously never came to fruition. The second one, the infamous Construction 501/503, aka The Dead Railway, from Salekhard to Igarka, was started in 1947 using slave labor of prison inmates.