School Bus Hours : The vehicle hours of travel by revenue vehicles while serving as a school bus. School bus hours are only hours where a bus is primarily or solely dedicated to carrying school passengers
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}