Top speed for trains in regular service is currently 305 km/h (190 mph), though the infrastructure is designed for 350 km/h (217 mph). The initial rolling stock was based on Alstom's TGV Reseau, and was partly built in Korea. The domestically developed HSR-350x, which achieved 352.4 km/h (219.0 mph) in tests, resulted in a second type of high-speed trains now operated by Korail, the KTX Sancheon. The next generation KTX train, HEMU-430X, achieved 421.4 km/h in 2013, making South Korea the world's fourth country after France, Japan and China to develop a high-speed train running on conventional rail above 420 km/h.