From BBC News (link):
The completion of the Tibet railway is being hailed in China as one of the world’s great engineering marvels. The longest high-altitude railway in the world, it will ease access to the remote region. Test runs are due to begin on 1 July.
Tibet’s extraordinary isolation has kept it poor. Education levels and life expectancy fall well behind the rest of China. But that isolation has also helped to preserve Tibet’s unique culture and way of life.
The arrival of the railway will bring tremendous change. China’s communist rulers say it will open up Tibet, bringing greater prosperity for its entire people. Detractors say the opening of the railway is the death knell of an independent Tibetan culture.
See also – “Oxygen to be offered in trains on world’s highest railway” by Xinhua News Agency; – “China completes railway to Tibet” by BBC News.