High-speed rail moves millions throughout the world every day – but in the US, high cost and low use make its future bumpy

The Amtrak NextGen Acela is a new high-speed train that runs between Washington, D.C. and Boston. Saul Loeb/AFP via Getty Images

High-speed rail systems are found all over the globe. Japan’s bullet train began operating in 1964. China will have 31,000 miles (50,000 kilometers) of high-speed track by the end of 2025. The fastest train in Europe goes almost 200 mph (320 kph). Yet high-speed rail remains absent from most of the U.S.

Stephen Mattingly, a civil engineering professor at the University of Texas at Arlington, explains why high-speed rail projects in much of the country so often go off track.