 With a gradual plan, the CR brand is going to replace the current CRH brand in service.Depending on their speed, there are 3 categories of high speed trains, G,D and C (G being the fastest at 350 km/h, D having a speed of 250 km/h and C having a speed of 200 km/h).High-speed rail services were first introduced in 2007 operating with CRH rolling stock.