High-speed rail

One of the most expensive factors limiting speed is curve radius. Many railway lines were built in the 19th century following river valleys or other features or had to avoid encroaching on the land of certain landowners and are thus rather curvy. In mountainous areas lines were sometimes deliberately built curvy to allow heavy and underpowered steam trains to climb the slopes, sometimes with spirals where long trains would pass over themselves. Engineers in several countries were tasked with allowing trains to go faster on existing or only moderately upgraded track either to deliver HSR earlier to more people or to avoid the daunting investment of new construction.

England, which had a curvy legacy network but was at the time averse to spend much on infrastructure and Italy, which has the Alps in the North and the Apennines along its spine were at the forefront of this development. Both countries saw the solution in a train tilting to decrease lateral forces, similar to what motorcyclists do. There was the question of "active tilt", i.e., the carriages being tilted by motors hydraulics and so on or "passive tilt" where the carriages would be moved by the inertia of the train entering the curve. British Rail developed the "Advanced Passenger Train" (APT), the first train with active tilt in passenger service. However, the APT was plagued with teething issues, among them motion sickness experienced by journalists on a test run, and thus the project was canceled and the patents sold to Italian companies. The Italians meanwhile developed a series of trains with passive tilt called "Pendolino", which has become the generic name of tilting trains in many languages, even though it is still trademarked. Italian tilting train technology enjoys a good reputation and is exported to the British Isles among other places.

Not all tilting trains meet the common definitions of high speed rail but they are usually the fastest trains on any given route. In some countries — notably Germany — there have been problems with certain tilting trains leading to the tilting mechanism being disabled or their premature withdrawal from service.

• Morocco began a high-speed TGV service between Tangier and Casablanca in 2018. It is run by ONCF, the state railway.

See also: Rail travel in China

• China Railway High-speed (中国高速铁路) (CRH) – The only high-speed trains in the world that offer sleeper cabins on longer routes due to the vast distances covered. Cross-border services run via Guangzhou and Shenzhen to West Kowloon Railway Station in Hong Kong. A line from Kunming to Vientiane, Laos opened in 2023, crossing the border into Laos at Mohan/Boten, before continuing on to Vientiane via the popular tourist destinations of Luang Prabang and Vang Vieng. However, speeds on the Lao section are limited to 160 km/h.

The first high-speed rail line in Southeast Asia, the Jakarta-Bandung high-speed rail, began operations on 1st October 2023. Plans have been mooted to extend the line onward to Surabaya, but construction has not begun on the extension yet.

See also: Rail travel in Japan

• Shinkansen (新幹線), also known as the bullet train. The original high-speed rail service, operated by the JR companies that are the privatized successors of Japan's state railways. Trains are fast, clean and on time, but prices are higher than in Europe or other Asian countries. While the network reaches all of Japan's main islands it is low on links outside of the main length of the main islands. The shinkansen finally reached Hokkaido in 2016 and extensions further into the island are planned are to open gradually until the early 2030s. While Japan's legacy rail network is built to 1,067 mm (42.0 in) gauge, all Shinkansen lines are built to standard gauge due to the higher requirements of faster trains.

The Haramain High Speed Railway connects Islam's two holiest cities, Mecca and Medina via Jeddah and King Abdullah Economic City. Non-Muslims cannot enter Mecca, but can travel between Jeddah and Medina.

Main article: High-speed rail in South Korea

High-speed rail in South Korea is a good and fast way to get to the places it covers. However, be prepared to pay somewhat costly fares.

• Korea Train eXpress (한국고속철도) (KTX). The KTX is often promoted as an indigenous Korean development, though it is in truth derived from the TGV. The Seoul - Busan route in particular helped ease congestion on one of the country's busiest highways and reduce flights on one of the world's busiest flight corridors. Proposals for an undersea tunnel to Jeju are variously made due to the immense popularity of the island and the strain flights to Jeju put on domestic airport capacity.

• Taiwan High Speed Rail (台灣高速鐵路) (THSR), built using Japanese Shinkansen technology. A single line connects the north and south of the island along its western shore. The THSR has led to the elimination of domestic flights along the west coast. Early bird fares offer discounts up to 35% of the regular walk-up fare which is less of a spread than the difference between early bird and walkup fares in Europe but still unusual for east Asian HSR.

Turkish State Railways' Yüksek Hızlı Tren (YHT) (literally high-speed train) has three routes in operation originating in Ankara. One links to several stations on both sides of the Bosphorus in Istanbul via Eskişehir and another branches off from that line to serve Konya. The third extends east to Sivas. Tickets tend to be rather affordable, but trains can book out rather quickly, so you should book ahead even though prices are fixed. Plans to extend the network as well as construction are underway.

A 334 km (208 mi) line links three major cities in Uzbekistan. From the capital Tashkent, trains travel at speeds of up to 250 km/h (160 mph) to Samarkand and Bukhara. Trains are operated on the Russian gauge by Uzbekistan Railways.

See also: Rail travel in Europe

Europe is the only continent with a truly international high-speed rail network, and therefore has several operators linking multiple countries together. There is a reasonable level of integration and cooperation between these companies, allowing passengers to purchase through-tickets on journeys that use more than one company and cross several borders.

• Renfe's AVE connects Spanish cities to destinations in southern France: Avignon, Lyon, Marseille, Montpellier, Toulouse.
• Eurostar connects Belgium, France, Germany, the Netherlands and the United Kingdom. Eurostar absorbed Thalys in 2024. Services to and from the UK require passengers undergo border and security controls, whereas EU-only services operate the same as any domestic train. Major cities served: Amsterdam, Antwerp, Brussels, Cologne, Düsseldorf, Liège, Lille, London, Lyon, Marseille, Paris, Rotterdam.
• The Deutsche Bahn ICE crosses into most of Germany's neighbors (Austria, Belgium, France, the Netherlands and Switzerland, but not Luxembourg, Poland, or the Czech Republic). Major cities served outside of Germany: Amsterdam, Basel, Bern, Brussels, Innsbruck, Paris, Salzburg, Strasbourg, Vienna, Zurich.
• Railjet trains cross from Austria into some neighboring countries, namely the Czech Republic, Germany, Hungary and Italy, but are limited to 160 km/h (99 mph) outside of Austria and Germany due to infrastructure concerns. Major cities served: Budapest, Munich, Prague, Venice, Vienna, Zurich.
• SNCF's TGV crosses borders into many of France's neighbors, namely Belgium, Germany, Italy, Luxembourg, Spain and Switzerland (where the service is known as TGV Lyria). The service between France and Germany is jointly operated by the SNCF and Deutsche Bahn, with ICE and TGV trains running on both sides of the border. A similar arrangement works between the SNCF and Spanish company Renfe for journeys between France and Spain. Major cities served outside of France: Barcelona, Basel, Brussels, Frankfurt, Geneva, Luxembourg, Milan, Munich, Stuttgart, Turin
• The Swiss, German and Italian railways jointly run a train service with a top speed of 250 km/h (160 mph) from Frankfurt to Milan and back once daily. The service is branded as Eurocity Express by DB but shows up as a normal EuroCity in Swiss and Italian schedules. Tickets can be bought and schedules in English obtained from Deutsche Bahn. Intermediate stops include Mannheim, Karlsruhe, Basel and Bern, plus several resort towns in western Switzerland.

While several new and upgraded lines have a design speed of 250 km/h, actual maximum speed in daily operations is limited to 230 km/h, which is reached by the Austrian locomotive hauled Railjet and ICE trainsets operated by ÖBB (Austrian State Railways) and Deutsche Bahn (German State Railways). The fare structure of ÖBB is similar to DB, though sometimes walk-up fares are a bit cheaper.

Due to the country's small size, Belgium's high-speed network is centered around international services, and accordingly all high-speed services in the country are operated by foreign companies (Deutsche Bahn, Eurostar, and SNCF) rather than by the National Railway Company. Brussels is nonetheless connected domestically to Antwerp and Liege by high-speed lines.

See also: Rail travel in France

The French national rail company SNCF operates the famous Train à Grande Vitesse (TGV) to most major cities in the country, along an extensive network of purpose-built lines (270-320 km/h) and in part along older and much slower lines. There is also a low-cost high-speed service run by the SNCF but separate to the TGV, called Ouigo, which operates from Marne-la-Vallée (near Disneyland Paris) on some routes north, west and south. Most lines connect to one of the great Paris termini on one end. The erstwhile rapid pace of new construction has slowed down considerably and President Macron has publicly questioned the need for any high speed lines beyond those already existing.

See also: Rail travel in Germany

Deutsche Bahn's Intercity-Express (ICE) operates to many cities around Germany, though the network is slightly less well-developed than other European countries (but catching up fast). The older Intercity trains are capable of speeds up to 200 km/h and are not marketed as "high-speed" even though similar trains in other countries get this designation. On specific routes there are "ICE Sprinter" which only stop at major cities and are usually fast enough to be more attractive to business travelers than planes. In December 2017 a new line opened slashing travel times between Berlin and Munich from six hours to less than four which saw an enormous increase in passengers, the line carrying one million people in its first hundred days. The German ICE trains largely follow something called Taktfahrplan in German - in essence that means that trains will leave in regular intervals (e.g. one train every hour, every half hour, every two hours or the likes) which makes it much easier to memorize schedules. Work to ensure connections "fit perfectly" at major interchange stations (like they do in Switzerland) is ongoing as of 2020 and will likely not be anywhere close to completion by 2030.

See also: Rail travel in Italy

Italy is served by two high-speed rail companies. The Frecciarossa is run by Trenitalia, the Italian national railway company. Nuovo Trasporto Viaggiatori (NTV) is a private company, with Ferrari being one of the investors. They serve their routes with a TGV-derived train known as the Italo.

See also: Rail travel in the Netherlands

Due to its small size, high-speed rail in the Netherlands is primarily centred around international services. The Netherlands has one dedicated high-speed line and a number of improved traditional railway lines. Services are operated by Deutsche Bahn and Eurostar (formerly Thalys), rather than by Nederlandse Spoorwegen. High-speed Eurostar trains run between Amsterdam and Rotterdam Centraal stations, via Schiphol Airport, and across the border into Belgium. ICE Trains from Germany run along traditional-speed lines. There was a brief period in late 2012/early 2013 when a train under the name "Fyra" was run as the Dutch high-speed rail service, however, technical problems caused the service to be withdrawn after barely a month of service. Since then, the "Fyra" trains have been replaced by refurbished intercity cars that run on the high-speed line at a lower speed (160 km/h compared to 300 km/h on the Eurostar). New trains running at 200 km/h top speed are expected to replace the intercity cars from 2020.

Russian Railways' Sapsan (Сапсан) has services from Moscow to St. Petersburg. The line to Nizhny Novgorod was served by Sapsan trains, but now the somewhat slower Strizh (Стриж) trains run at 200 km/h top speed. A few Strizh services run all the way to Berlin. Some other lines are either under construction or planned, including the Moscow–Kazan line which could be the first section of a high-speed line to Beijing.

Renfe's Alta Velocidad Española (AVE) is one of the largest systems in the world, second only to China in total length. While the economic crisis since 2008 has slowed the boom of new construction for the time-being (and the connection to Portugal has been put on hold indefinitely), Renfe has lowered prices to keep passenger numbers up. In addition to AVE, there is also Avant with top speeds up to 250 km/h. Spanish high speed rail operates on standard gauge to ensure compatibility to the French network, but there are trains capable of changing onto the broad gauge legacy network.

Switzerland, being small, compact and very mountainous, has no high-speed rail lines except for two tunnels mainly intended for freight, though it does receive ICE and TGV trains from Germany and France respectively, which make use of classic lines. The Lötschberg Base Tunnel allows trains to run at 250 km/h along its 35-km length. Similarly, the Gotthard Base Tunnel, while primarily intended for freight trains, has a design speed of 250 km/h which makes it a "high-speed" line. It shortens many trips through the Alps by half an hour and relieves freight bottlenecks, despite its short length compared to other high-speed lines. Switzerland's national railway SBB has since acquired rolling stock capable of top speeds of 250 km/h which is marketed under the name "Giruno" (derived from the Romansh word for buzzard) on international routes to/from Italy using the Gotthard Base Tunnel. The train is also planned to receive certification for Germany and Austria some time 2020 or 2021.

See also: Rail travel in Great Britain

The UK has one high-speed line, between London St Pancras station and the Channel Tunnel. Domestic services are operated on the line by Southeastern Highspeed between London, Canterbury, Dover and several other towns in Kent. The trains, nicknamed the "Javelin", operate at 140 mph (225 km/h). Other intercity routes marketed as "high-speed" or "express" are slower, generally operating at a maximum speed of 125 mph (200 km/h). Indeed, new intercity trains being introduced on two main lines are capable of 140 mph but are limited to 125 mph due to infrastructure concerns. Although a national high-speed rail network is approved by Parliament and under construction, it is not scheduled to open until 2026, with later phases opening in 2027 and 2033.

While high-speed rail services have been proposed in Canada and Australia, the popularity of private car ownership and air travel, as well as political wrangling, mean that high-speed rail is likely to remain a distant dream for the foreseeable future.

In the United States, Amtrak's Acela service on the Northeast Corridor between Boston and Washington has trains that briefly achieve a top speed of 150 mph (240 km/h), but due to its relatively low average speed, is not generally considered a high-speed service. Brightline connects Miami and Orlando, Florida, with a top speed of 125 mph (201 km/h). Brightline West, which is expected to open in 2027, is planned to link Las Vegas and the Los Angeles area with a top speed of 180 mph (290 km/h). California High-Speed Rail (CAHSR) is under construction in California to connect the Central Valley towns of Bakersfield and Merced via Fresno, with completion expected in 2029. The privately-owned Texas Central Railway, meanwhile, is actively acquiring land to build a Shinkansen line (in partnership with Japan Rail) connecting Dallas and Houston in under 90 minutes, at a top speed of 205 mph (330 km/h). Completion is optimistically expected in 2026, but as of 2022, construction has yet to start.

India began construction of its first high speed rail line in 2017 between Mumbai and Ahmedabad, using Japanese Shinkansen technology allowing up to 300 km/h (190 mph). The first sections of the line may open in 2027, and there are ambitious plans to extend the network nationwide in the 2030s.

Australia has been talking about high-speed rail since the 1980s, with grand plans announced before elections and quietly shelved soon thereafter. The 2022 iteration envisions a line starting between New South Wales's two largest cities of Sydney and Newcastle, with eventual plans to extend the line north towards Brisbane and southwest towards Melbourne, but construction has yet to start.

In other parts of the world, high-speed rail links are often 'announced' as part of a larger infrastructure investment, and then quietly dropped later.