6,800 miles of fast track

china high speed rail 1

In the six years since China opened its first high-speed rail line, the country's network has grown to 6,800 miles of dedicated track -- making it by far the world's largest system.

The scale of the project is simply massive, but it has also produced hundreds of billions of dollars in debt, a deadly accident and allegations of corruption.

January 29 2015 05:06 PM ET