Much analysis of accident data and most crash tests focus on single impacts. However, in reality, multiple impacts account for a large proportion of serious injury accidents and are expected to become a larger proportion as countermeasures, developed primarily for single mode impacts, take effect. It is proposed that multiple impacts should be considered separately since consideration of their characteristics may have implications for occupant protection.

This study investigates multiple impacts in more detail and, in particular, explores their relative importance in the accident population, analyses their characteristics and discusses some possible consequences for occupant protection measures.