Source: International Union of Railways
- First phase (development of twin cities corridors). Most high speed rail systems are initially developed to connect the most important cities that are within 300 to 500 km. Japan saw the first comprehensive development of a high speed train system along the Tokyo - Osaka corridor in 1964. High speed rail services started in Europe in 1991, with two corridors between Paris and Lyon and Paris and Dijon. About half of all the world's high speed passengers-kms are now occurring in Europe. For Asia, the first corridors were set in 2004 for South Korea, in 2007 for Taiwan and in 2009 for China (Chinese data not available).
- Second phase (interconnection). The success of the first phase usually incites the development of additional HSR segments and their growing interconnection. This may however represent some risks. For instance, by the 1990s the usage of HSR in Japan peaked, in part because of competition from air transport and limited economic growth. Japan was facing diminishing returns as new high speed lines were servicing smaller cities and lower density areas. For Europe, interconnection was more successful as systems were developed in Italy, Germany, Belgium and the Netherlands. China represents a unique case where the system rapidly developed and interconnected, so the Chinese HSR by-passed the first phase.