In just over a decade, Beijing is set to have the most extensive subway network in the world. That may not shock you, this is China, after all, unless you know, as Lloyds recent post reminds us, that Beijing currently has one of the worlds weakest subway networks. The city is so large and the system is so limited that public transit penetration lingers at 30 20 percent, less than half that of most of the worlds developed cities.

As Beijings car population grows with its ring roads (Beijing is now hitting its sixth ring), stretching and clogging the city, planners are worried; by 2020 they are aiming for a subway web 561 km big, which will be wider than that of Londons (if not, we imagine, more sublime than Moscows aging soviet underground). Though the cost of the expansion has not been calculated, even before the 2008 Green Olympics brings a million visitors to the city, Beijing is expected to spend somewhere between 200-250 billion RMB on transportation upgrades, including new bus lines and the new subway lines 4 and 5. (The current cost of a subway ticket in Beijing: 3 RMB, about 40 US cents.)

If the subway expansion doesn’t work, there’s always the world’s largest underground city and road network…

While the subway plan may not be surprising to those familiar with Chinas passion for large numbers and larger superprojects (like the almost complete Three Gorges Dam), the chances of this actually happening seem as slim as a Beijing fried noodle. And while far from a silver bullet in Beijing, with its poor planning and Los Angeles-style sprawl, the subway project is impressive and badly needed.

In that category however, it already has a formidable rival: one of the worlds largest planned aqueducts. The South-to-North Water Diversion Project will cost over RMB 500 billion ($62 billion) and will bring water from the Yangtze River to the Chinese capital, which by some estimates is more parched than Israel. According to the China Daily.