Title: The feasibility and effectiveness of belt pretensioning and load limiting for adults in the rear seat

Authors: Richard Kent, Jason Forman, Daniel P. Parent, Shashi Kuppa

Addresses: Department of Mechanical and Aerospace Engineering, Center for Applied Biomechanics, University of Virginia, 1011 Linden Avenue, Charlottesville, VA 22902, USA. ' Department of Mechanical and Aerospace Engineering, Center for Applied Biomechanics, University of Virginia, 1011 Linden Avenue, Charlottesville, VA 22902, USA. ' Department of Mechanical and Aerospace Engineering, Center for Applied Biomechanics, University of Virginia, 1011 Linden Avenue, Charlottesville, VA 22902, USA. ' US Department of Transportation, National Highway Traffic Safety Administration, 1200 New Jersey Avenue, SE, Washington, DC 20590, USA

Abstract: The US Fatality Analysis Reporting System (FARS) and State Data System (SDS) for Florida, Pennsylvania and Maryland were utilised to estimate relative fatality rates and injury risk ratios between the front and rear-seat passengers, and a parametric study of rear-seat restraint parameters was performed to assess chest deflection and head excursion trends. The fatality and serious injury risk in frontal crashes is found to be higher for older occupants in rear seats than for those in front seats. In addition, the relative effectiveness of rear seats is lower in newer vehicle models, presumably due to the advances in front-seat restraint technology. The simulations demonstrate that injury risk in the rear seat can be reduced by incorporating front-seat restraint technology (load limiting and pretensioning), even in the absence of an air bag and knee bolster. A force-limiting belt with a pretensioner can maintain or reduce head excursion relative to a standard belt, while reducing thoracic injury risk. In fact, 42 sets of restraint parameters were identified that reduced both head excursion and chest deflection relative to the baseline belt.

Keywords: passive safety; rear seats; occupant protection; thoracic injuries; older occupants; seat belts; load limiters; pretensioners; vehicle safety; fatality rates; injury risk ratios; rear seat restraints; chest deflection; head excursion; simulation.

DOI: 10.1504/IJVS.2007.016749

International Journal of Vehicle Safety, 2007 Vol.2 No.4, pp.378 - 403

Published online: 21 Jan 2008 *

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