The Construction and Transportation Ministry says a domestically developed tilting train has gone 20,000 kilometers in test runs.

The ministry will complete the test runs next year after they cover 100,000 kilometers. The trains will go into operation in 2010.

Unlike other models, the trains maintain speed when handling curves by tilting inward, overcoming centrifugal force.

The trains are quasi-electric bullet trains, which can run 180 kilometers per hour. They will be first put into service on the Chungbuk, Gyeongbu, Honam, Jeolla and Joongang railways.