ANN ARBOR—A new University of Michigan study lends further credence to the belief that rear-seat passengers are better off than their front-seat counterparts in car crashes.

In an analysis of frontal collision data from 1980-91, researchers Donald Huelke and Charles Compton of the U-M Transportation Research Institute found that, when comparing front-seat occupants and rear-seat passengers—both belted and unrestrained—in the same crash, those in the back seat more often than not sustain less severe injuries than those in the front seat.

“The rear seat is a much safer area in frontal crashes than the front,” Huelke says. “Lap-belted rear-occupants have a higher level of injury severity less often than lap/shoulder- belted front-seat occupants in the same crash. In fact, it appears that unbelted rear passengers fare as well as lap/shoulder-belted front-seat occupants in the same frontal crashes.”

Using the Maximum Abbreviated Injury Scale (MAIS), which measures severity of vehicle crash injuries, Huelke and Compton found that, in direct comparisons, 21 percent of belted front- seat occupants suffered greater injuries than belted rear-seat passengers, while 8 percent of the latter fared worse than those wearing safety belts in the front. The remaining 71 percent had about the same level of injury.

In comparing unbelted occupants, the injury rates were 29 percent for those in the front seat and 11 percent for those in the back. The remaining 60 percent sustained the same level of injury.

“Our data disagree with prior research that the injury severity for unbelted front and rear-seat occupants is similar,” Huelke says. “Our findings indicate that the unrestrained rear-seat occupant injury frequency is about 63 percent lower than unrestrained front-seat occupants.”

While 31 percent of front-seat occupants not wearing lap/shoulder belts received greater injuries than belted rear- seat passengers (only 6 percent of the latter fared worse than unbelted persons in the front seat and 63 percent had the same level of injury), the rates were the same for those wearing safety belts in the front compared with those not wearing them in the back—17 percent of each group suffered greater injuries (66 percent had the same level of injury).

Huelke found that children, ages 5-14, are more likely to sustain injuries in crashes when seated in the front compared with the back, regardless of safety belt use.

In comparing children seated in the back with adults in the front, 7 percent of the former and 20 percent of the latter received more severe injuries in cases where both were belted (73 percent had same level of injury). When both were not wearing safety belts, 31 percent of those in the front seat and 8 percent of those in the back suffered greater injuries (61 percent had same level of injury).

Corresponding injury rates for those passengers unbelted in the front compared with children wearing lap belts in the rear seat is 25 percent (front), 5 percent (back) and 70 percent

Ironically, 36 percent of belted front-seat occupants sustained greater injuries than unrestrained children in the back, while just 14 percent of the latter had greater injuries than those in the front (50 percent had same level of injury).

“Overall, the bottom line is you’re better lap-belted in the back seat than being unrestrained,” Huelke says. “Everyone should always wear the available belts. People in the back seat, whether they be adults or children or infants in child-restraint systems, should always be appropriately buckled up.”