High-speed rail
High-speed rail is a type of rail transport that operates significantly faster than traditional rail traffic, using an integrated system of specialized rolling stock and dedicated tracks. While there is no single standard that applies worldwide, new lines in excess of and existing lines in excess of are widely considered to be high-speed, with some extending the definition to include lower speeds in areas for which these speeds still represent significant improvements. The first such system began operations in Japan in 1964 and was widely known as the bullet train. High-speed trains normally operate on standard gauge tracks of continuously welded rail on grade-separated right-of-way that incorporates a large turning radius in its design.
Passenger rail terminology
The higher-speed rail can operate at top speeds that are higher than conventional rail but the speeds are not as high as those in the high-speed rail services. These services are provided after improvements to the conventional rail infrastructure in order to support trains that can operate safely at higher speeds. There is no globally accepted standard in the speed ranges for this classification. Local and regional jurisdictions may have their own definitions. For example, a definition in North Texas has a wide range of speeds between and . A planned construction in Thailand, called medium-speed rail, has the top speeds of .