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 Europe
Many of the newly built railway lines in Sweden are adapted for speeds up to 250 km/h, such as Botniabanan, Grödingebanan, Mälarbanan, Svealandsbanan, Västkustbanan, and Vänernbanan.
The problem that is slowing down high-speed rail in Sweden is the present signaling system (ATC), which does not allow speeds over 200 km/h. It can be upgraded, but it will not be done since it shall be replaced by the European signaling system ERTMS level 2 on major lines in the near future, allowing high speeds up to 250 km/h. ERTMS level 2 has been installed and is being tried out on Botniabanan, and that railway allows 250 km/h, although no passenger train goes above 200 for now. The train set X55-Regina has been delivered to the rail company SJ with the max speed of 200 km/h but with the option to upgrade the EMU to 250 km/h when possible. Also the mix with freight trains slow down the practical speed.