China's first sky trains came off the assembly line in the city of Nanjing on September 10, 2016, with China becoming the third country to master sky train technology, after Germany and Japan.

The two compartments can hold more than 200 passengers, and when compared with subways and trams, sky trains have lower costs, better climbing and turning ability, and higher wind resistance.

Professor Yue at the Beijing Jiaotong University said the construction period of sky trains is also much shorter than that of subways, lasting only three to five months for dozens of kilometers of rails.

The overhauled railway is driven by batteries which can run for four hours at a time, and the batteries can be changed when stopped at a station, with the whole process lasting only two minutes.

The sky trains are to debut in China next year at a variety of scenic places.