Decompartmentalising road safety barrier stiffness in the context of vehicle occupant risk

Road safety barriers are selected for deployment on the basis of four basic criteria; costs, deflection performance, containment capacity, and severity outcomes. System specific severity risk to occupants of errant vehicles is not well established. Contemporary technical governance in the Australian context recognizes three generic barrier types discerned by relative stiffness: rigid, semi-rigid, and flexible. This study explores how the occupant severity indicator Acceleration Severity Index (ASI) varies as a function of impact configuration and system stiffness. This study demonstrates that systems available to road safety practitioners may be better served by a continuum rather than a generic classification system.