By any measure, Beijing’s Subway system is an impressive feat of engineering, with its 14 lines, 172 stations and 336 kms of track in operation. It first opened in 1969 and is the oldest subway in mainland China, and the second in length after the Shanghai Metro.

Small wonder, though, that with 1.8 billion rides recorded in 2010, and with a single-day record of 7.57 million rides in September this year, you’ll be very lucky to find a seat at almost any time of day, while in rush hours you regularly have to fight just to get into a carriage.

I was brought up using London’s Underground system – popularly known as The Tube. It is the oldest underground railway in the world, the first section of which opened in 1863. With its 270 stations and 402 kms of track, it is the second largest metro system in the world in terms of route miles, after the Shanghai Metro. In 2007, more than one billion passenger journeys were recorded, making it the third busiest metro system in Europe, after Moscow and Paris. Yet, outside rush hours, it is usual to be able to get a seat, if not for your entire journey, then at least for a portion of it.

The Paris Métro, on the other hand, is literally a work of art, with its architecture influenced by the Art Nouveau movement of the 1930s. Paris has one of the densest metro networks in the world, with 245 stations lying within an area of 87 square kms.

The first line opened in July 1900, during the World Fair (Exposition Universelle) and the Métro quickly expanded to complete its core system by the 1920s. Famed for its carriages that run on rubber tires, the trains may be a bit rickety, but they are nonetheless quite comfortable.

The (relatively) “new kid on the block” much closer to home is of course Hong Kong’s Mass Transit System which only opened in 1979. I well remember on my first visits to the territory in the early 1970s having to take buses and ferries everywhere, and taking an age to be able to do so. The coming of the MTR was popular with practically every resident and totally transformed life in the region.

What particularly makes Beijing’s system stand out from the crowd, though, is the cheapness of its fares. At only two yuan for any journey, regardless of the distance covered, surely no one can really complain about the level of overcrowding. A distance that I regularly travel in Beijing for that measly two quai would cost the equivalent of RMB40 in London, RMB30 in Hong Kong and RMB25 in Paris.

So despite its rapid expansion, accelerated by the Chinese government's ¥4 trillion economic stimulus package, the existing network is hard pressed to adequately meet the city's mass transit needs. Already there are plans to have 19 lines and over 660 km of track in operation by 2015 which will surely go a long way to improving the lot of the everyday commuter.

New lines, or sections of lines, are due to open very shortly – something I am particularly looking forward to as I live close to line 10 which is soon to encircle a very large area of Beijing.

But one thing I always wonder, when looking at the overall subway system map, is why the planners have stuck so rigidly to a grid plan – whereby you travel north-south or east-west, but where there is little scope to travel diagonally across the city. Everyone knows that the shortest distance from A to B is in a straight line; and traveling along the two sides of a rectangle rather than along the hypotenuse considerably increases any journey time.

Perhaps there is a perfectly rational explanation why this cannot be achieved, but looking at the plans for Beijing’s subway system over the next five years it is clear that this is not scheduled for the immediate future. By the time the planners actually get round to achieving this I fear I will have long departed these shores.