Ch 59. Train Control and Rail Traffic Management Systems
Alessandro Neri
Alessandro Neri
Overview
Accurate knowledge of the train’s location is a key element in increasing the efficiency of a rail traffic management system. The higher the accuracy, the smaller the safety distance between two trains on the same line, and therefore, the higher the supported traffic density. Conventional technologies based on equipment deployed track‐side are so expensive that their economical sustainability is limited to high‐speed lines. Recently, the attention of the railways regulatory bodies has been focused on GNSS, because its integration into modern train control systems is expected to produce a significant cost saving. This could enable an annual rate of railway market expansion 1.5 times higher than would have been possible by the adoption of traditional track‐side technology.
This fact motivated the adoption by the European Union Agency for Railways of the EGNSS (European Global Navigation Satellite Systems) assets into the European Rail Train Management System (ERTMS). ERTMS is considered the safest and most advanced train control system. It was originally developed and standardized in Europe to assure full interoperability of the signaling system across the European Union, and then spread all over the word, including China, India, Taiwan, South Korea, and Saudi Arabia.
Similarly, in the United States, GPS technologies have been incorporated into several types of Positive Train Control (PTC) systems, like the Electronic Train Management Systems (ETMS), the Interoperable Electronic Train management System (I‐ETMS), and the Incremental TCS (ITCS). The PTC is a processor‐based/communication‐based TCS designed to prevent train accidents, which has to be installed and implemented on Class I railroad main lines (i.e. lines with over 5 million gross tons annually) over which any poisonous‐ or toxic‐by‐inhalation hazardous materials are transported; and, on any railroad’s main lines over which regularly scheduled passenger intercity or commuter operations are conducted.