Railroad : Consists of two steel rails which are held a fixed distance apart upon a roadbed. Vehicles, guided and supported by flanged steel wheels, and connected into trains, are propelled as a means of transportation
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}