The safest seat in the car and child restraint systems
July 2006

In a full car, some poor soul is relegated to the middle of the back seat, the least desirable, most uncomfortable, most "un-cool" spot in the vehicle. It also happens to be the safest.

University of Buffalo researchers studied all auto crashes involving a fatality in the U.S. between 2000 and 2003 where someone occupied the rear middle-seat.

They found that occupants of the back seat are 59 percent to 86 percent safer than passengers in the front seat and that, in the back seat, the person in the middle is 25 percent safer than other back-seat passengers.

After controlling for factors such as restraint use, vehicle type, vehicle weight, occupant age, weather and light conditions, air-bag deployment, drug results and fatalities per crash, the rear middle seat was still found to be 16 percent safer than any other seat in the vehicle.

Results of the study were presented at the May meeting of the Society for Academic Emergency Medicine in San Francisco, California.  Researchers at the Center for Transportation Injury Research (CenTIR), conducted a retrospective cohort study of fatal crashes in which there were rear-seat occupants and at least one fatality in the vehicle. The data was obtained from the Fatality Analysis Reporting System of the National Highway Traffic Safety Administration.

The study involved two different sets of fatal crash data. Researchers first analyzed a special class of car crashes in which there were occupants in the front seat and in the middle of the back seat. Fatal crashes in which there was no occupant in the rear middle seat were excluded. This class of crashes involved 27,098 occupants. Researchers compared survival rates of front-seat versus back-seat positions.

The second data set compared survival rates of back-seat occupants only in crashes in which there was at least one fatality. The middle-seat group contained 5,707 occupants, while the "outboard" or window-seat group had 27,611 occupants, for a total of 33,318 back-seat passengers.

The fatality rate for the rear middle-seat occupant then was compared to that of the window-seat positions. The analysis produced some revealing statistics, aside from the issue of the safest place to be sitting during a crash. The average age of the 33,318 rear seat passengers was 20 years, while middle back-seat passengers were only 15.4 years on average.

Nearly half of the passengers in the back seat -- 46.9 percent -- were not wearing seat belts, results showed, and of these unrestrained passengers, 34.6 percent were fatally injured, compared to only 14.9 percent of seat-belt wearers.

In general, back-seat passengers who wore seat belts were 2.4 to 3.2 times more likely to survive a crash than their unbelted back-seat companions.

This study reinforces the importance of using seat belts in the back seat, as well as demonstrating that the rear middle seat is the safest. Legislation to require rear-seat belt use by all passengers should be strongly supported.

Child safety seats reduce risk of death in crashes more than seat belts alone.

Young children involved in car crashes may have a greater chance of survival if secured in a child restraint system, such as a safety seat than if buckled only in a seat belt.

Policy for child car safety relies on evaluating the risks of not using safety seats versus the benefits of their use in protecting children in crashes. These safety evaluations are often conducted using the U.S. Department of Transportation Fatality Analysis Reporting System (FARS), a census of car crashes in which one or more persons died. Using only FARS data for these evaluations, however, can be problematic, because these data assume that surviving children in fatal crashes were secured similarly to those of children in other, non-fatal crashes.

Researchers from the University of Michigan, Ann Arbor examined vehicle crash data to compare the benefit of using child restraint systems (such as safety seats) to wearing seat belts alone in children two to six years old.

The study sample comprised 7,813 children in fatal crashes from the FARS database and 1,433 children in nonfatal crashes from the National Automotive Sampling System Crashworthiness Data System (NASS CDS), all of whom were involved in crashes in which at least one car was left undriveable between 1998 and 2003.

Overall, approximately one in 1,000 children in a two-way crash died, with less than half (45 percent) of all children in restraint seats. One of six children (15.7 percent) were in the front seat, two thirds (67.6 percent) were in passenger cars, one of six (15.6 percent) were in pre-1990 model year vehicles and 4 percent of cars were driven by teenage drivers.

Child restraint systems offer improved fit of restraints for children who are too small for the adult-sized seat belt, thereby affording a mechanical protection advantage over seat belts.

However if restraint systems are seriously misused, their safety performance would be expected to be diminished.

Based on past and these current findings, efforts should continue to promote child restraint use through improved laws and educational programs.



Bibliography:

1. University at Buffalo

2. Federal Highway Administration

3. Center for Transportation Injury Research

4. Society for Academic Emergency Medicine

5. Archives of Pediatrics & Adolescent Medicine 2006; 160: 617 – 621. June 2006

6. University of Michigan