High-speed rail (HSR) is a type of rail transport that runs significantly faster than traditional rail traffic, using an integrated system of specialised rolling stock and dedicated tracks. While there is no single standard that applies worldwide, purpose-built lines in excess of 250 km/h (155 mph) and upgraded 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 a grade-separated right-of-way that incorporates a large turning radius in its design. However, certain regions with wider legacy railways, such as parts of the former Russian Empire, have sought to develop a high speed railway network in Russian gauge. Thus far no high speed rail is planned or has been built on narrow gauge with the Spirit of Queensland achieving the highest top speed in revenue service on Cape gauge at 160 km/h.