Side Impact Protection and Belt Positioning Boosters for Children

The aims of this study were to evaluate the effectiveness of Belt Positioning Boosters in side impact, and to determine the scope for improving their performance by incorporating improved anchorage systems. As part of this evaluation, the need for inclusion of side impact testing in regulatory and consumer test programs was assessed. Two of the most commonly used high back booster seats in Australia, a convertible blow molded plastic booster (BS #1) and a molded polystyrene booster (BS #2) were tested in 90° and 45° side impacts with different anchorage mechanisms. In addition to the conventional anchorage system (which consists of only the three point seat belt to anchor BS#1 and a top tether in addition to the three point seat belt to anchor BS#2), three additional anchorages were tested - a rigid ISOFIX, a semi-rigid system consisting of a continuous loop through the base of the booster (semi-rigid #1) and a semi-rigid system consisting of two flexible straps on the sides of the base of the booster (semi-rigid #2). Top tethers were used in all rigid/semi-rigid configurations. A Hybrid III 6 year-old-dummy, instrumented with sensors to measure head acceleration, neck forces and moments, was used in all tests. The motion of the dummy and restraint systems was captured using a high speed digital camera at 500 frames per second. Resultant head acceleration, resultant neck force and moment, HIC, and the motion of the dummy and the booster seat, were evaluated. High back belt positioning boosters tested do not appear to provide greatly improved protection in side impact compared to a three point seat belt alone because of poor head and torso containment. In most of the tests conducted in this program, the dummy was not adequately contained within the booster. This work has also demonstrated that scope does exist for improving the protection provided by belt positioning boosters in side impact through rigidly anchoring the booster seat to the vehicle and improving the geometry of the side wings. However, for this potential to be fully realized, belt positioning booster seats must be able to better contain the dummy (or child) during the impact. It should be noted that, while only commonly used Australian belt positioning boosters were used in this test series, booster seats of these types are also used in other countries. The study has shown that there is a clear need for improved booster seat designs to achieve higher levels of side impact protection for children between 4 and 8 years old and that particular attention should be placed in developing head protection suitable for the entire age range of children using belt positioning boosters. It also showed that the level of protection provided by belt positioning booster seats can be improved through the use of rigid anchorage systems. These results also demonstrated that more attention should be placed on the performance of boosters in side impact internationally, and that there is a need for inclusion of side impact evaluation in regulatory and consumer test programs. For the covering abstract see ITRD E141807.