It is well known that in the rear seat of cars, small children squirm, slide, slump, sleep, play and interact with their fellow passengers. Our previous findings from a pilot study show that children rarely remain in an optimal position for the efficient functioning of their restraint systems throughout the duration of their journey. Such behaviours may not only affect restraint effectiveness but may also have a negative influence on driver performance and distraction. Moreover, quantification of children’s position and out-of-position (OOP) status (i.e., their actual position relative to the ideal position for which the technology was designed) has important implications for design of test programs using anthropomorphic test devices (ATD) intended to mimic the human occupant. For example, understanding true pre-crash positions may lead to different design specifications of rear seat restraint systems and energy management features of the vehicle interior compared with the kinds of solutions that might arise from evaluations with an in-position ATD. This paper builds on our preliminary research findings and describes the design of the first international large-scale study of children in cars which uses innovative methods to observe and quantify the positions of child occupants in cars and identify the injury effects of OOP status and its impact on driver distraction. The study will facilitate a paradigm-shifting advance in child occupant protection – from the concept of safety technology designed to protect an ideally positioned occupant to the concept of dynamic restraint systems that maintain optimal restraint over a range of expected child positions/movements in a vehicle. Outcomes of the research will directly inform the design of future restraints for children, the development of appropriate crash test procedures that account for natural positions of child occupants, and the development of community awareness messages to improve the safety of children
