The early 19905 was a period which saw the rapid introduction of improved occupant restraint systems into Australian vehicles. However, even in 1995, by which date nearly all US passenger vehicles were equipped with single or twin airbags, most Australian vehicles only offered a single airbag, and in most cases this was optional equipment. A few models offered twin airbags, most also optional equipment.

There has therefore been a limited opportunity to examine the difference in results between otherwise identical vehicle models with and without airbags in NCAP tests.

It has also become evident that crash dummy head to knee impacts are much more comnon in the Australian NCAP than in the US NCAP. This is mainly due to the difference in the rate of airbag fitment noted above, and again there is a valuable npportunity to gain useful knowledge about occupant restraint systems by examining the circumstances of the head tn knee impacts experienced in the Australian NCAP.

This paper examines the difference in NCAP injury scores between otherwise identical vehicle models with and without and analyses the reasons for dummy head tn knee contacts in NCAP full frontal tests. From these analyses sume suggestions are made to improve occupant restraint performance.