An updated evaluation of the effects on predicted injuries of an example crush protective device (CPD) proposed for application to All-Terrain Vehicles (ATVs) is described. As in previous evaluations, this involved extending and applying the test and analysis methods defined in ISO 13232 (2005) for motorcycle impacts, to evaluate the effects of the example CPD in a sample of simulated ATV overturn events. Updated modeling refinements included lowering the energy levels of the simulated overturn events; accounting for potential mechanical/ traumatic (compressive) asphyxia mechanisms; refining and calibrating the force-deflection characteristics of helmet, head, legs and soil so as to reduce potential over-prediction of head and leg injuries; and calibrating the simulation against aggregated injury distributions from actual accidents. Approximately 3,080 computer simulations were run, and the results indicated that, for the simulation sample and in comparison to the helmeted baseline ATV, addition of the example CPD created injury and fatality risks that were greater than its injury and fatality benefits. This study also confirmed results of other research indicating that helmet wearing has substantial net injury benefits, and a low risk/benefit percentage, confirming the importance, effectiveness and low additional injury risk of helmet wearing.