A number of developing countries will increasingly become rich in the 21st century together with developed countries, to consume much more energy in the life of people, and for production and transport. Railways are expected to play an important role in high-speed passenger, commuter, suburban and freight transport. If the share of railways is enhanced, energy consumption and emission of CO₂ will be cut in the field of transport. To have the railway transport accepted more positively by people, it is important to ceaselessly develop rolling stock technologies to improve the convenience of users, reduce noise and vibration, save energy and establish EMC and reliability of the railway system.