Historically, assessments of frontal crash safety have been based primarily on the measured responses of 50th percentile male dummies in relatively high speed vehicle crashes against a rigid flat barrier. Under such test conditions, the ability of supplementary airbag systems to greatly reduce head injury potential is clearly evident in crash tests performed by Transport Canada and others. However, significant segments of the driving population travel routinely with their seats positioned ahead of the nominal mid-position used in 50th percentile male dummy tests. Moreover, most frontal impacts can be expected to produce softer vehicle deceleration signatures than those produced in flat rigid wall tests. The necessity of broadening the range of regulated crash conditions to which vehicles fitted with airbag systems are subjected is highlighted in crash tests performed by Transport Canada using 5th percentile female Hybrid III tests, with seats placed in their most forward postions. The neck loads observed in these tests far exceeded commonly referenced injury assessment values. The magnitudes of the neck loads were influenced not only by the aggressiveness of the airbag system, but also by the timing of the deployment of the airbag. The neck loads observed in low speed offset frontal crash tests often exceeded those observed in high-speed, rigid-wall tests, as a result of the timing of airbag deployment. (A)
Abstract