This paper summarises the results of a project on vehicle crash compatibility, run by European automotive industry together with some research institutes. The project was funded by the European commission as BE97-4049.

There are three main issues that can be detected in real world accidents, influencing vehicle compatibility. These issues are mass differences, compartment integrity with regard to frontal car-to-car impact, and differences in bumper and sill height in side impact. Longitudinal mismatch in frontal impact, front end stiffness and other items which are from a theoretical point of view responsible for vehicle aggressiveness are not seen influential from the view point of real world accidents.

On the other hand, compartment collapse occurs, when there is not sufficient deformation energy available in vehicle front-end. And deformation energy is available, when it is provided by vehicle structures and when these structures interact. So compartment collapse can only be avoided, as long as sufficient deformation energy is available and is effective within the car-to-car collision.

So the paper will provide results with regard to the questions of deformation management. It will give guidelines for future research on compatibility, which has to focus on the problem of structural interaction.