Major gains in occupant protection in automotive crashes have been made over the past few decades, with the introduction of technologies such as airbags and seat belt pretensioners. However, the focus, both in terms of regulation and consumer testing, has been on front seat occupants. With rear seat occupants being over-represented in vehicle fatalities, there is a need to examine protection offered to those who sit in the back seat of motor vehicles.

This thesis consists of six inter-related studies focused on characterising the rates and biomechanical mechanisms of the injury to rear seat occupants (not using child restraints), and evaluations of both existing and novel technologies for improving injury outcomes for rear seat occupants. The methods used include in-depth crash investigation and crash sled testing, with a focus on children aged 8-16 and older occupants.

The results of these studies indicate that substantial casualty savings in rear seat occupants might be achieved through the implementation of existing technology to front seat occupants. While the results of the in-depth crash investigation demonstrated that injury mechanisms differ between front and rear seat occupants, it was found from sled testing that tailoring existing technologies to meet the needs of rear seat occupants, such as younger and older occupants, may substantially improve rear seat occupant protection. Vehicle regulation and consumer testing has previously been an effective method for driving improvements in occupant protection, and it is recommended that vehicle regulation bodies incorporate requirements for performance of the rear seat occupant protection system.