Source: Adapted from International Union of Railways.
High Speed Rail (HSR) systems are built to reinforce accessibility and connectivity within well developed regional urban systems, many which are mega urban regions They fill a gap between short range mobility provided by cars and buses and medium range mobility provided by air transport. There was as of 2016 more than 34,800 km of operational HSR lines in the world with an additional 24,800 km under construction. These lines were initially set as corridors between city-pairs and their growth eventually lead to integrated systems spanning extended regions, such as for Japan, Coastal China and Western Europe. While services remain designed along corridors, nodes where it is possible to effectively switch from one corridor to the other are emerging. Like air transport, a good frequency of high speed services enables these interconnections to occur effectively. HSR systems are mainly found in three regions of the world where they have contributed in shaping intercity mobility:
- In Asia, the urban density factor is the most suitable for the development of HRS systems, with most cities well above 5,000 people per square km. Japan was the innovator and from 1964 a national integrated HSR system was built along dedicated lines to service the major cities and three of the four main islands of the Japanese territory. Both South Korea and Taiwan have built HSR to service as a corridor between their two largest cities. China has embarked in an ambitious plan to build a national HSR system that is showing a growing level of integration. The Chinese HSR system has grown rapidly and is already the world’s most extensive with 31,000 km being operational as of 2019. For instance, the world’s longest HSR service between Beijing and Guangzhou was inaugurated in December 2012, taking approximately 8 hours to link both cities. For China the development of an HSR system was seen as a national priority because of growing mobility demands, the lack of transport infrastructure and highly congested standard rail and air transport routes. India has several high speed corridors planned, but high capital requirements and securing rights of way are serious challenges.
- In Europe, urban density is average with cities usually above 3,000 people per square km. The setting of HSR systems has gradually permitted a growing level of integration, particularly between the highly urbanized regions of France, Belgium, the Netherlands and Germany. The completion of the Eurotunnel in 1994 enabled to link London to the European HSR system. Northern European countries (Norway, Sweden and Finland) have mostly developed their HSR system through the reconversion of existing lines, a strategy that reflects the relatively short distances involved and lower population densities. As the European system is getting more integrated, HSR hubs connecting different corridors are emerging, notably Brussels.
- In North America, urban density is low, commonly below 2,000 people per square km. Only one high speed rail corridor is an operation in the high density Boston – Washington corridor, but technical requirements limit the speed along several segments (the New York – Washington segment can be considered high speed). The setting of HSR corridors linking regional urban systems has been debated for more than two decades, with many corridor projects clearly identified and advocated (e.g. San Francisco-San Diego, Quebec-Toronto, Miami-Orlando-Tampa or Vancouver-Seattle-Eugene). Yet, the prominence and relatively low cost of road and air transport has been factors playing against the development of HSR. The density of North American cities, including their central areas, is low and it remains debatable if this density is sufficient to justify large scale HSR projects. Another important impediment to the development of HSR systems in North America is the dominance of freight with the rail network owned and operated by private companies. This leads to right of way conflicts in the vicinity of major metropolitan areas, which have also important intermodal and bulk terminal facilities.