The PRISM project is a European Commission funded 5th Framework project that is intended to determine appropriate smart restraint technologies for Europe.

This paper describes a volunteer study undertaken as part of the PRISM project. The purpose of the study was to gain an understanding of how passengers “brace” and react during pre-impact vehicle manoeuvres (emergency braking, rapid lane changing etc.). This information, linked to real world occupant photographic studies, gives indications of real world postures at impact that can be considered for smart restraint systems.

A total of 49 volunteers were driven in an instrumented test car and were subjected to fierce pre-impact manoeuvres without warning. Each volunteer undertook 3 tests over a period of time either from their own normal postures, from pre-defined postures, or whilst undertaking various tasks.

Project staff, aware of the tests and in control of the severity and the frequency of the tests, undertook higher risk tests including unbelted and extreme out of position tests. Also 6 crash test ATDs of different sizes were subjected to the same vehicle manoeuvres, so that their inertial behaviour could be compared with human behaviour. In all, 230 tests were undertaken, with each test being filmed from 5 on-board cameras.

The development of the test methodology is described and the drawbacks of the earlier concepts are explained, together with the improvements made. The strengths and limitations of the tests and results are also explained.

Following a discussion of the results, a number of conclusions have been drawn, regarding both human behaviour and the strengths and limitations of using crash ATDs for pre-impact work. These conclusions have implications for managing occupant postures at the commencement of impact events.