The Beijing Subway is a rapid transit rail network that serves the urban and suburban districts of the Chinese capital. But now, it's about to phase out all old carriages and replace them with new air-conditioned ones. Four new rail lines are also being added to the transport system.

The Beijing Subway is a rapid transit rail network that serves the urban and suburban districts of the Chinese capital.

It's just another regular day for subway driver Zhang XiaoYu. This marks the 12,960th day he has been on the tracks. In the past 36 years, he has witnessed the evolution of the Beijing Subway system.

Zhang XiaoYu said, "I have driven every type of train since the day I started working for Beijing Subway. From the oldest type without ventilation to the latest air-conditioned train Triple-V-F which makes it more comfortable for passengers, the new train uses less electricity and is more environmental friendly. "

I was fortunate enough to try out the driving simulator on the latest model the triple-V-F. Zhang said the subway was originally for tourism purposes, but it has become an essential public transport tool for everyone here in Beijing.

Zhang XiaoYu said, "I think the passenger load has grown exponentially in recent years, especially during the morning and evening peak hours.”

To ease road traffic, the government has set a policy to restrict purchase of private cars. Over 5 million people use the subway every day. So that combined with a cheap 2 yuan fare has driven up the number of subway passengers significantly.

The Beijing Subway is a rapid transit rail network that serves the urban and suburban districts of the Chinese capital.

In response, Beijing Metro spokesman Jia Peng says the total mileage of the subway will be over 450 kilometres with the additional lines.

Jia Peng said, "By the end of 2012, Beijing will open four new subway lines, the new lines will significantly expand the subway's coverage, especially south and west of the city. one will be parallel to the current line 1 which crosses the entire Chang'an Street. Line 10, when fully completed, will form a complete loop around Line 2."

The opening of new lines also benefits real estate agencies.

"The property sales and rental business is getting better, especially with the opening of more subway stations which enable residents to travel more efficiently."

However network operations also posts great challenges.

"With the opening of the peripheral lines, more passengers will flow into the city, adding more pressure to subway stations, especially for stops like us - the intersection between urban and rural areas - the passenger flow is immense."

Jia says there's currently a push towards quality improvement for the entire subway system.