Main Track : (1) A designated track upon which trains are operated by timetable, train order, or both, or the use of which is governed by block signals; and (2) Main Line
Ilan Kelman (ed.), Vulnerability and Resilience Definitions and References, Version 2, 2007. http://www.islandvulnerability.org/docs/vulnres.pd f, (Vulnr and Resilience - Brit) {524}