With rail services already capturing passengers who might otherwise have flown, even the airline bosses are talking up their potential.

The new rail link that is causing problems for China Southern Airlines could indicate the kind of competition that many Chinese carriers will face in the future. The high-speed Guangzhou-Wuhan service, which opened in December, cuts the 660-mile (1,070km) journey from 11 hours to three. China Southern, which has China's biggest fleet, responded at first by adding flights, slashing prices and speeding up check-ins, but many customers nonetheless switched to the train. And now the airline is reportedly considering scaling back its new flights and selling bundled air and train tickets.