During the past 40 years, different child restraint systems (CRS) have been developed to improve protection for children of different sizes and ages. Development of more effective CRS, and a higher frequency in use of the restraints, in addition to enhanced vehicle safety, has resulted in an increased level of child safety.

This study examines accident data with Volvo cars in Sweden to evaluate child safety with respect to age, size and impact situation (including impact severity in frontal impacts);​ identifying optimal restraints as well as potential areas needing more attention. A total of 3670 children, aged 0-15 years, involved in car crashes 1987-2004 were selected from Volvo's statistical accident database.

The injury-reducing effect of the child restraint systems was high overall. The highest injury-reducing effect was found in rearwardfacing child restraints for children up to 3-4 years of age, offering an injury-reducing effect of 90% compared to an unrestrained child. Beltpositioning boosters from 4 to 10 years of age were found to have an injury reducing effect of 77%.

Compared to adults, this study indicates that children have a generally lower AIS 2+ injury rate, except for abdominal and lower-extremity injuries. Abdominal injuries are mainly found in children using only a seat belt, emphasizing the need for belt-positioning boosters.

A tendency of higher injury risk was found when the growing child switches from one restraint to another, i.e. when the child is at the youngest age approved for the restraint. Thus, the total injury-reducing effect would increase if all children were to use the child restraint system most appropriate for their size and age. The challenge is to spread information as well as enhance design to encourage everyone to use the appropriate child restraint system and to use it correctly.