The Beijing Subway system, the country's oldest, is undergoing an unprecedented expansion ahead of the Summer Olympics.

CNN: Beijing commuters feel the squeeze

This month TDSi won a contract to make control equipment, readers and software for 12 subway stations in Beijing, having already supplied kit for metro systems in Shanghai and Tianjin.

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The government is massively upgrading the public transportation network (see a map of the planned subway expansion) as part of this expansion of Greater Beijing.

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Average daily commuting times in Beijing -- which boasts one of the country's larger subway networks -- are 79 minutes, roughly double the OECD average.

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Since the middle of last year, Beijing has been accelerating approvals for infrastructure investment, notably for railway and subway networks, to stimulate the economy.

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As far as the preferred mode of public transportation goes, however, Tsao belongs to a growing number of Beijing residents who are opting for the slower bus to the supposedly far more efficient subway.

CNN: Beijing commuters feel the squeeze