Before talking about the new media that appears in the Beijing METRO lately. Let's make a short introduction about what is the Beijing metro right now: It is 10 lines of Metro with the latest opening of the line 4 ( the numbers have nothing to do with the number of existing lines).
When I arrived in Beijing in 2004 , there were only 2 lines ( Blue and Red). Then the Line 13 opened a year later and the preparation for the Olympics led to the opening of a few more. Let's have a look below of what was the situation end of 2009 for the subway network. ( Many thanks to www.chinatouristmaps.com for providing the great maps in this article)

subway bj 2009