High-speed rail (HSR) is a type of rail transport that runs 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 250 km/h (155 mph) and existing lines in excess of 200 km/h (124 mph) are widely considered to be high-speed. The first high-speed rail system, the Tōkaidō Shinkansen, began operations in Japan in 1964 and was widely known as the bullet train. High-speed trains mostly operate on standard gauge tracks of continuously welded rail on grade-separated right-of-way that incorporates a large turning radius in its design, however certain regions with wider legacy railways, such as Russia have sought to develop a high speed railway network in broad gauge.
Several countries have built and developed high-speed rail infrastructure to connect major cities, including Belgium, China, Denmark, France, Germany, Italy, Japan, Morocco, the Netherlands, Poland, Russia, Saudi Arabia, South Korea, Spain, Sweden, Taiwan, Turkey, the United Kingdom, the United States and Uzbekistan. Only in Europe does high-speed rail cross international borders. China had built over 37,900 kilometres (23,500 mi) of high-speed rail as of December 2020, accounting for more than two-thirds of the world's total.
High-speed rail is the fastest ground-based commercial transportation. China has the fastest conventional high-speed rail in regular operation, with the Beijing–Shanghai high-speed railway reaching up to 350 km/h. The Shanghai Maglev Train, opened in 2004, is the fastest commercial passenger maglev in operation, at 430 km/h. In 2007, the Euroduplex TGV trains broke a record of 574.8 km/h, making it the fastest conventional-wheeled train. The Chuo Shinkansen in Japan is a maglev line under construction from Tokyo to Osaka at commercial speeds of 500 km/h, with operations due to start in 2027.