Shanghai metro: 52km in under two minutes

Smart and modern, trains on Shanghai's new metro line 16 reach up to 120km/h (75 mph).

The line is opening this week, and along with a partial stretch of line 12, it makes the city's metro system the first in the world to cover a total length of more than 500 km (310 miles).

The network now extends far into the suburbs despite the first bit of track having been laid little more than 20 years ago.

But with dozens of other Chinese cities now expanding or building their own metro systems some observers have raised doubts about the cost of it all.

If nothing else, it is a sign that there is little let-up in big government spending despite all the talk of the need to rebalance China's economy.

The debate will rumble on. But for now, BBC News saves you the 8 RMB fare it costs to travel the 52km (32.5 miles) from one end to the other on line 16.

Hop on board the newest part of the world's biggest subway system.