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NASS/CDS data (1993-2013) was used to examine serious injury rates and injury sources for belted drivers in near- and far-side impacts. Frequency and severity of near- and far-side impacts by crash severity (delta-V) were compared for older (1994-2007 MY) and newer (2008-2013 MY) vehicles. For 2008-2013 MY, individual cases were examined for serious thorax injury in far-side impacts. Results show that, for newer passenger cars, about 92% of side impacts have a delta-V under 15 mph and, for older cars, the percentage is about 86%. The rate of serious injury is higher for nearside compared to far-side crashes for both older and newer models, and the near-side injury rate is much lower for newer models. Safety features, including side airbags, are effective in reducing injuries to near-side belted drivers in newer models. The serious injury rate for near-side belted drivers in older cars is 5.5% for near-side crashes and 1.2% for far-side crashes.

This paper updates the findings of prior research addressing the relationship between seatback strength and likelihood of serious injury/fatality to belted drivers and rear seat occupants in rear-impact crashes. Statistical analyses were performed using 1995-2014 CY police-reported crash data from seventeen states. Seatback strength for over 100 vehicle model groupings (model years 1996-2013) was included in the analysis. Seatback strength is measured in terms of the maximum moment that results in 10 inches of seat displacement. These measurements range from 5,989 in-lbs to 39,918 in-lbs, resulting in a wide range of seatback strengths. Additional analysis was done to see whether Seat Integrated Restraint Systems (SIRS) perform better than conventional belts in reducing driver and rear seat occupant injury in rear impacts. Field data shows the severe injury rate for belted drivers in rear-impact crashes is less than 1%.

To determine the relationship between seatback stiffness or strength and the likelihood of serious/fatal injury for drivers and rear seat occupants in rear-impact crashes, analyses were performed using 1995-2006 police-reported crash data from eleven states. Seatback stiffness and strength data was included for 29 different seatback designs used in 40 vehicle models (model years 1995-2006). Results indicate there is no statistically significant relationship between seatback stiffness or strength and the risk of serious/fatal injury in rear-impact crashes. Factors shown to have statistically significant effect on the likelihood of serious/fatal injury in rear-impact collisions include occupant age, gender, and alcohol impairment; vehicle type; and vehicle mass ratio.

As part of a comprehensive plan to reduce the risk of death and serious injury in rollover crashes, NHTSA has proposed upgrading the roof crush resistance standard, FMVSS 216. To evaluate the benefit of this proposal, the agency examined real-world data on injuries and fatalities that would be prevented by the proposed rulemaking. This paper provides a detailed discussion of the statistical and engineering approaches used to derive benefit estimates on fatalities calculated by NHTSA for the proposed upgrade. It concludes the NHTSA estimate of 13-44 lives saved annually is not reliable due to extreme sensitivity of the benefit calculation to the paucity of field data and questionable engineering assumptions.

Various factors were evaluated to determine their influence on the odds of front seat occupants receiving either fatal or serious/fatal injuries in single-vehicle rollovers. Factors evaluated included roof strength-to-vehicle weight ratio (as measured in accordance with FMVSS 216), and SAE H61 Effective Headroom. Roof strength-to-weight ratio had no statistically significant effect (p>0.05) on the likelihood of fatality or serious/fatal injury for belted or unbelted drivers. SAE H61 Effective Headroom had no statistically significant effect (p>0.05) on the likelihood of fatal or serious/fatal injury for seat belted drivers in rollovers.