Geometrical specifications and infrastructure for high speed railways

Today it is now possible to operate trains with 360 km/h on railways. High speed railways geometric specifications, infrastructure and superstructure are different from conventional railways. These geometric specifications, infrastructure and superstructure are required to achieve these speeds. This work is compiled with Turkish and English sources. The content of the work is divided into conventional railway and high speed railway. The geometric specifications, infrastructure and superstructure of conventional railways are given in the second section. So that it helps to understand much better the general information of railways. The information regarding to high speed railway is given in another section and it is referred to conventional railways when needed. As a result, maintanence period and maintanence cost of high speed lines should be profitable, transition areas should be taken into consideration and the construction should at least match with the TSI specifications. Keywords: Railway infrastructure, railway superstructure, high speed railway, track geometry, Technical Specification for Interoperability.