Roadbed Material : The material below the subgrade in cuts and embankments and in embankment foundations extending to such depth as affects the support of the pavement structure
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}