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.
High-speed rail in the United Kingdom
At present, a mixture of Eurostar international services and Southeastern domestic passenger services use High Speed 1. Attempts to increase speeds to on both the East Coast Main Line (ECML) and West Coast Main Line (WCML) have all failed, partly because trains that travel above are considered to require in-cab signalling for safety reasons. The term High Speed Train (or HST125) is currently also used as a brand name for the present British fleet of Class 43 InterCity diesel trains.