? After consulting the information, I think there are three main reasons. The first reason is the high altitude of the Qinghai-Tibet Plateau. Topographically, the railway is like a road leading to heaven, so it is said to be a road leading to heaven. The second reason is that the construction is difficult, and many worldwide problems are concentrated together. Building is more difficult than going to heaven, saying it is heaven; The third reason is that Tibet is called a paradise on earth. This road seems to bring people into paradise on earth, so it is called heaven.
I think the Qinghai-Tibet Railway is called Tianlu because of its high terrain and difficult construction, which seems to be the road to paradise on earth.