Contents
DISCLAIMER 2
LIST OF ABBREVIATIONS 5
EXECUTIVE SUMMARY 6
1. Description, history, and previous studies of curtain and side air bags 8
1.1. Curtain and side air bags designed to deploy in side impacts 8
1.2. Rollover curtains 10
1.3. Relevant FMVSS and consumer information programs 11
1.4. Installation history 12
1.5. Previous studies 15
1.6. Analysis outline 17
2. Analyses of near-side impacts 18
2.1. Logistic regression analyses for near-side impacts 18
2.1.1. General description 18
2.1.2. FARS database 19
2.1.3. The principal regression analysis for near-side impacts 23
2.1.4. Alternative regression analyses 29
2.3. FARS/GES analysis for curtain + torso bags in near-side impacts 36
2.4. Conclusions: near-side impacts 37
3. Analyses of far-side impacts 37
3.1. Logistic regression analyses for far-side impacts 39
3.2. Contingency table analysis for curtain + torso bags in far-side impacts 41
3.3. FARS/GES analysis for curtain + torso bags in far-side impacts 42
3.4. Discussion: far-side impacts 43
4. Preliminary analyses of rollover curtains 43
4.1. Logistic regression analyses for first-event rollovers 44
4.2. Contingency-table analyses for first-event rollovers 48
4.3. Analyses of fatal ejections in first-event rollovers 50
4.4. Analyses of subsequent-event rollovers that are not side impacts 51
4.5. Analyses of rollover curtains in near-side impacts 53
4.6. Analyses of rollover curtains in far-side impacts 55
4.7. Preliminary conclusions: rollover curtains 57
Appendix A. Curtain and Side Air Bags, by Type, MY 1996-2011 58
Appendix B. Make-Models in the Contingency-Table and FARS-GES Analyses 86
Appendix C. Make-Models in the Contingency-Table Analyses of Rollover Curtains 88
Table 1. Percent of Vehicles Equipped With Side Air Bags, by Model Year (1995 to 2011 FARS data: vehicles involved in fatal crashes) 13
Table 2. Near-Side Fatality Cases Available for NHTSA's 2007 Report 15
Table 3. Near-Side Fatality Cases Available for This Report and for the 2007 Report 23
Table 4. Estimated Overall Fatality Reduction (%) in Near-Side Impacts, by Type of Side Air Bags 28
Table 5. Estimated Fatality Reduction (%) in Near-Side Impacts By Type of Side Air Bags and Vehicle Type 30
Table 6. Estimated Fatality Reduction (%) in Near-Side Impacts By Type of Side Air Bags and Seat Position 31
Table 7. Estimated Fatality Reduction (%) in Near-Side Impacts By Type of Side Air Bags in Two Regression Analyses 32
Table 8. Estimated Fatality Reduction (%) in Near-Side Impacts By Type of Side Air Bags in Two Regression Analyses With Different Control Groups 33
Table 9. Contingency-Table Analysis of Fatality Reduction by Curtain Plus Torso Bags in Near-Side Impacts (Non-Occupant Control Group) 35
Table 10. Contingency-Table Analysis of Fatality Reduction by Curtain Plus Torso Bags in Near-Side Impacts (Control Group. Longitudinal Impacts) 36
Table 11. Fatalities Per 1,000 Drivers and RF Passengers in Near-Side Impacts (1999-2011 FARS and GES data for make-models and MY listed in Appendix B) 37
Table 12. Far-Side Fatality Cases Available for This Report and for the 2007 Report 38
Table 13. Estimated Overall Fatality Reduction (%) in Far-Side Impacts, by Type of Side Air Bags 40
Table 14. Contingency-Table Analysis of Fatality Reduction by Curtain Plus Torso Bags in Far-side Impacts (Non-Occupant Control Group) 42
Table 15. Fatalities Per 1,000 Drivers and RF Passengers in Far-Side Impacts (1999-2011 FARS and GES data for make-models and MY listed in Appendix B) 43
Table 16. Fatalities in First-Event Rollovers, by Vehicle Type (FARS, CY 1999 to 2011, MY 2000 to 2011) 45
Table 17. Contingency-Table Analysis of Fatality Reduction by Rollover Curtains in First-Event Rollovers 49
Table 18. Reduction of Fatal Ejections by Rollover Curtains in First-Event Rollovers 51
Table 19. Fatalities in Subsequent-Event Rollovers That Are Not Side Impacts 53
Table 20. Fatality Reduction by Rollover Curtains in Near-Side Impacts (Make-models that shifted from non-rollover curtains plus torso bags to rollover curtains plus torso bags without changing ESC status) 55
Table 21. Fatality Reduction by Rollover Curtains in Far-side Impacts (Make-models that shifted to rollover curtains plus torso bags without changing ESC status) 56
Figure 1. Seat-Mounted Torso Bag 8
Figure 2. Door-Mounted Torso Bag 8
Figure 3. Torso Bag With Pelvis Protection 8
Figure 4. Curtain Air Bag (Narrow Span) 9
Figure 5. Inflatable Tube 9
Figure 6. Curtain Air Bag (Wide Span) 9
Figure 7. Combination Bag 9
Figure 8. Curtain Plus Torso Bags 10
Figure 9. Door-Mounted Head-Impact Air Bag 10
Figure 10. Percentage of Vehicles With Side Air Bags, By Model Year 14