The objective of this study was to compare head, neck, and chest injury risks
between front and rear-seated Hybrid III 50th-percentile male anthropomorphic
test devices (ATDs) during matched frontal impacts. Seven vehicles were
converted to rear seat test bucks (two sedans, three mid-size SUVs, one
subcompact SUV, and one minivan) and then used to perform sled testing with
vehicle-specific frontal NCAP acceleration pulses and a rear seated (i.e.,
second row) Hybrid III 50th male ATD. Matched front seat Hybrid III 50th male
ATD data were obtained from the NHTSA Vehicle Crash Test Database for each
vehicle. HIC15, Nij, maximum chest acceleration, and maximum chest deflection
were compared between the front and rear seat tests, as well as between vehicles
with conventional and advanced three-point belt restraint systems in the rear
seat. Additionally, a modified version of the NCAP frontal star rating was
calculated for the front and rear seat tests. All injury metrics, except for
chest acceleration, were higher in the rear seat compared to the front. In
addition, injury thresholds were exceeded or nearly exceeded in the rear seat
for Nij in three vehicles, chest acceleration in one vehicle, and chest
deflection in three vehicles, while no thresholds were exceeded in the front
seat. When comparing advanced and conventional restraints in the rear seat, all
injury metrics were higher in the vehicles with conventional restraints. All
vehicles with conventional restraints in the rear had a star rating of 1, while
those with advanced restraints in the rear ranged from 2 to 3. Conversely, all
vehicles had 5 stars for the front seat, except one that had 4 stars. Overall,
these data highlight the disparity between front and rear seat occupant
protection and the benefits of advanced rear seat safety restraints, and the
need for future testing.
