Recent United States Federal Motor Vehicle Safety Standards (FMVSS) have focused on rollover injury mitigation of passenger cars through vehicle stability control, improving roof structure strength requirements and occupant containment;​ however rollovers continue to be the most dangerous accident mode for heavy truck occupants when compared to other accident modes. Despite decades of recognition of this problem, there has yet to be any mandated standards dealing with heavy truck rollover safety. Damage to heavy truck roofs can occur from lateral loading as the vehicle rolls onto its side, vertical cab loading from friction while the vehicle is on its side as well as lateral and vertical loading as the vehicle rolls onto its roof. Throughout the rollover, there can be significant longitudinal cab loading due to the longitudinal component of the roof‐to‐ground impact as well as friction along the ground. In the presented paper, a real‐world heavy truck rollover accident is analyzed. The rollover resulted in a large degree of downward and rearward deformation about the cab floor. In the process of analyzing this rollover accident, the standard industry testing practices were considered as tools to reproduce this real world damage pattern but were ultimately deemed insufficient at inducing the type of crush necessary to match it.

In this paper, the authors present a new alternative testing method based on existing testing methodologies to evaluate heavy truck structural performance under the cab loading conditions which produce the rearward and downward cab damage pattern. For the heavy truck rollover accident study, a parametric test series was conducted. A production test was conducted to evaluate the cab strength and energy management under the subject load path. This test quantified the ability of the cab to resist deformation and the effect on the resultant residual survival space. Based on the results of this production test an alternative design cab was constructed using standard industry accepted reinforcing techniques. This alternative design cab was tested under identical conditions to evaluate the ability of the reinforcements to mitigate the degree of cab deformation and to maintain adequate residual survival space. These laboratory tests help to establish the force and energy levels of the selected rollover accident and demonstrate that alternative cab designs can significantly reduce roof crush and enhance survival space preservation under identical test conditions.