Rear-Seat Motor Vehicle Travel in the U.S. Using National Data to Define a Population at Risk
Background
Recent studies suggest that the relative protection offered by rear seating in motor vehicle crashes has decreased, potentially reflecting disproportionate advancements in front-seat safety technology. Safe adaptation of advanced front-seat restraint systems for the rear-seat environment will require exposure data that are currently unavailable.
Purpose
This study uses national data to quantify rear-seat occupancy patterns, restraint use, and annual travel exposure in the U.S. in order to support the development of advanced crash protection systems for rear-seat motor vehicle occupants.
Methods
Data from the 2000–2006 National Automotive Sampling System Crashworthiness Data System and 2001 National Household Transportation Survey were analyzed in 2008 to quantify occupancy patterns (e.g., seat position, restraint use) and annual person-trips for rear-seat passengers in the U.S.
Results
The overall proportion of person-trips by rear-seat occupants is relatively low (12.9%); however national at-risk exposure remains significant (approximately 39 billion annual person-trips). Annual rear-seat travel exposure is similar among children ≤12 years and adults (18.9 vs 19.1 billion person-trips) despite the fact that children are proportionally much more likely to ride in rear positions (79.3% vs 7.4%). Restraint use among adult rear-seat occupants was also much lower than among front-seat occupants (50.4% vs 82.2%).
Conclusions
While rear-seat occupancy is relatively low compared with front-seat occupancy at-risk rear-seat travel by both child and adult passengers in the U.S. remains significant. Restraint use by rear-seat occupants is much lower than that among front-seat passengers, particularly among adults and older children, substantially increasing injury risk. Development of future crash protection systems for rear-seat passengers must account for these exposure patterns to ensure safe and effective integration into production vehicles.
Department of Emergency Medicine, University of Virginia Health School of Medicine and Center for Applied Biomechanics, University of Virginia School of Engineering, Charlottesville, Virginia
Address correspondence and reprint requests to: Matthew Trowbridge, MD, MPH, Department of Emergency Medicine, University of Virginia Health System, P.O. Box 800699, Charlottesville VA 22908-0699
ABSTRACT