So this was kind of discussed elsewhere within in the context of the newly expanded Panama Canal. It is China’s attempt to build on overland Silk Road type railway via Iran to Europe.
You can see from the article that the speeds are pretty uncompetitive with the newly expanded Panama Canal. 14 Days to reach Tehran from China and once they have the link to Baghdad built, who knows how long to reach Central Europe.
Here is the article from the Economist:
http://www.economist.com/news/middle-east-and-africa/21695765-some-treats-ahead-railway-enthusiasts-iranu2019s-new-continent-spanning
Right through areas controlled by Al Qaida, the Talban and ISIL (and their enemies) that have been hotbeds for conflict since well before the advent of Islam. Somehow I get the idea that the Chinese leadership has somewhat underestimated the size of the political-military problem. The engineering challenges are NOT the major challenges along that route.
Chuck