U.S. Department of Transportation National Highway Traffic Safety Administration ____________________________________________________________________________________________ DOT HS 810 748 January 2007 NHTSA Technical Report An Evaluation of Side Impact Protection FMVSS 214 TTI(d) Improvements and Side Air Bags ____________________________________________________________________ This document is available to the public at the Docket Management System of the U.S. Department of Transportation. The United States Government does not endorse products or manufacturers. Trade or manufacturers’ names appear only because they are considered essential to the object of this report. Technical Report Documentation Page 1. Report No. 2. Government Accession No. 3. Recipient’s Catalog No. DOT HS 810 748 4. Title and Subtitle 5. Report Date AN EVALUATION OF SIDE IMPACT PROTECTION January 2007 6. Performing Organization Code FMVSS 214 TTI(d) Improvements and Side Air Bags 7. Author(s) 8. Performing Organization Report No. Charles J. Kahane, Ph.D. 9. Performing Organization Name and Address 10. Work Unit No. (TRAIS) Evaluation Division; National Center for Statistics and Analysis National Highway Traffic Safety Administration 11. Contract or Grant No. Washington, DC 20590 12. Sponsoring Agency Name and Address 13. Type of Report and Period Covered Department of Transportation NHTSA Technical Report National Highway Traffic Safety Administration 14. Sponsoring Agency Code Washington, DC 20590 15. Supplementary Notes 16. Abstract Federal Motor Vehicle Safety Standard 214, “Side Impact Protection” was amended to assure occupant protection in a 33.5 mph crash test and phased-in to new passenger cars during model years 1994-1997. A Thoracic Trauma Index, TTI(d) is measured on Side Impact Dummies seated adjacent to the impact point. Manufacturers upgraded side structures and affixed padding in cars to improve TTI(d). Later, they installed two types of side air bags – torso bags and head air bags – for additional occupant protection in cars and LTVs. Statistical analyses of 1993-2005 crash data from the Fatality Analysis Reporting System (FARS) and the General Estimates System (GES) estimate fatality reductions for these technologies. • Average TTI(d) improved in 2-door cars from 114 in 1981-1985 to 44 in 214-certified cars with side air bags, and in 4-door cars from 85 to 48. • TTI(d) improvements without side air bags reduced fatality risk for nearside occupants in multivehicle crashes by an estimated 33 percent in 2-door cars and 17 percent in 4-door cars. • Torso plus head air bags reduce fatality risk for nearside occupants by an estimated 24 percent; torso bags alone, by 12 percent. • TTI(d) improvements, torso bags and head-curtain air bags could have saved an estimated 2,934 lives in calendar year 2003 if every car and LTV on the road had been equipped with them. 17. Key Words 18. Distribution Statement NHTSA; FARS; NASS; GES; FMVSS; statistical Document is available to the public at the Docket analysis; evaluation; benefits; effectiveness; fatality Management System of the U.S. Department of reduction; crashworthiness; angle collision Transportation, http://dms.dot.gov, Docket Number 27588. 19. Security Classif. (Of this report) 20. Security Classif. (Of this page) 21. No. of Pages 22. Price Unclassified Unclassified 178 Form DOT F 1700.7 (8-72) Reproduction of completed page authorized TABLE OF CONTENTS Acknowledgements.....................................................................................................................vii Executive summary......................................................................................................................ix 1. Occupant protection in side impacts.................................................................................... 1 1.1 The side impact problem in passenger cars ................................................................ 1 1.2 Side door beams: an early measure to protect occupants ......................................... 10 1.3 The dynamic test requirement for FMVSS 214........................................................ 11 1.4 Technologies to protect occupants in side impacts................................................... 14 1.5 What actually happened: average TTI(d), 1981-2002 .............................................. 17 1.6 Summary of the Phase 1 evaluation report ............................................................... 30 1.7 Braver-Kyrychenko and McCartt-Kyrychenko analyses of side air bags ................ 31 1.8 Evaluation goals........................................................................................................ 32 2. Effect of TTI(d) improvements on nearside fatalities in multivehicle crashes – after 1993, without side air bags........................................................................................ 35 2.0 Summary................................................................................................................... 35 2.1 A file of side impact test results for passenger cars.................................................. 35 2.2 Make-models that substantially improved TTI(d) without side air bags.................. 37 2.3 Fatalities per 1,000 nearside occupants in multivehicle side impacts ...................... 47 2.4 Nearside fatalities in multivehicle crashes relative to non-occupant fatalities......... 59 2.5 Analysis of compact pickup trucks........................................................................... 63 2.6 Best effectiveness estimates for passenger cars........................................................ 65 3. Effect of side air bags on fatalities and ejection in side impacts ....................................... 69 3.0 Summary................................................................................................................... 69 3.1 Car models that received standard or optional side air bags..................................... 69 3.2 Basic analyses of torso and head air bags in nearside impacts of cars ..................... 80 3.3 Fatality reduction by torso air bags in nearside impacts........................................... 94 3.4 Fatality reduction by torso bags plus head protection in nearside impacts............... 97 3.5 Fatality reduction in farside impacts of passenger cars .......................................... 105 3.6 Reduction of occupant ejection in side impacts...................................................... 117 3.7 Fatality reduction by side air bags in LTVs: early results ...................................... 119 3.8 Child passengers and side air bags.......................................................................... 120 3.9 Vehicles with head curtains only: early results....................................................... 121 3.10 Best effectiveness estimates.................................................................................... 123 iii 4. Lives saved and savable in 2003 by side impact protection ............................................ 127 4.0 Summary................................................................................................................. 127 4.1 A model for estimating lives saved and savable by side impact protection ........... 127 4.2 Parameters for the model ........................................................................................ 130 4.3 Results..................................................................................................................... 135 References ................................................................................................................................. 141 Appendix A: Make-model groups for evaluation of FMVSS 214........................................... 145 iv LIST OF ABBREVIATIONS ABS Antilock brake system AIS Abbreviated Injury Scale ANPRM Advance Notice of Proposed Rulemaking BMW Bayerische Motoren Werke CATMOD Categorical models procedure in SAS df Degrees of freedom DOT United States Department of Transportation EU European Union FARS Fatality Analysis Reporting System (a census of fatal crashes in the United States since 1975) FMH Free-motion headform FMVSS Federal Motor Vehicle Safety Standard GES General Estimates System of NASS GM General Motors GVWR Gross Vehicle Weight Rating (specified by the manufacturer, equals the vehicle’s curb weight plus maximum recommended loading) HIC Head Injury Criterion IIHS Insurance Institute for Highway Safety IR Information Request (from NHTSA) kph Kilometers per hour LTV Light trucks and vans (includes pickup trucks, SUVs, minivans and full-sized vans) MDB Moving deformable barrier mph Miles per hour v msec Milliseconds MY Model year NASS National Automotive Sampling System (a probability sample of police-reported crashes in the United States since 1979, investigated in detail) NCAP New Car Assessment Program (consumer information supplied by NHTSA on the safety of new cars and LTVs, based on test results, since 1979) NHTSA National Highway Traffic Safety Administration NICB National Insurance Crime Bureau NPRM Notice of Proposed Rulemaking NVPP R.L. Polk’s National Vehicle Population Profile PSU Primary sampling unit RF Right-front SAS Statistical analysis software produced by SAS Institute, Inc. SID Side impact dummy SUV Sport utility vehicle TTI Thoracic Trauma Index TTI(d) Thoracic Trauma Index for the dummy in a side-impact test VIN Vehicle Identification Number VMT Vehicle miles of travel vi ACKNOWLEDGEMENTS I owe special thanks