Passengers leave a train inside a station of the Olympic Line of Beijing Subway, July 28, 2008. [Xinhua]

Despite the security check, taking a ride on the Olympic Line is an enjoyable experience. The brand new train coaches seem more spacious than ordinary ones. Directions and stops are clearly signed in Chinese and English. Circuit television sets are equipped in each coach. The interiors of the four stations are decorated with the elements of a steel forest, giant water bubbles of the innovative national swimming venue, or an elegant arts arcade with big blue-and-white porcelain pillars.

Since Beijing's successful bid in 2001 for the summer Olympics, the municipal government has geared up upgrading its underground transport system.

A tiny portion, 23.6 kilometers, of the existing subway lines were built in 1965, primarily for defense purposes. The subway was opened to the public in 1981. The city now boasts about 200 km of subway and plans to extend the total lengthen to 561.5 km by 2020.