High-speed rails(HSR)are playing an important role in the transportation systems across the world.In Japan,the Shinkansens carry more than 250million passengers each year.In Europe,the trans-European high-speed rail network is in operation.At the beginning of 2011,U.S.President has called for a six-year,$53 billion budget for HSR.Nowadays,China has built the world’s largest HSR network of over 4 600 miles.Although it has been nearly half a century since the first high-speed train was inaugurated,HSR is still assimilating the most advanced technologies in High-speed rails (HSR) are playing an important role in the transportation systems across the world. In Japan, the Shinkansens carry more than 250million passengers each year. Europe, the trans-European high-speed rail network is in operation. At the beginning of 2011, USPresident has called for a six-year, $ 53 billion budget for HSR. Nowadays, China has built the world’s largest HSR network of over 4 600 miles. Though it has nearly nearly a half century since the first high- speed train was inaugurated, HSR is still assimilating the most advanced technologies in