Basic parameters that determine the occupant injury gravity, in a side crash are speed and the hit sidewall hardness. These two parameters are intimately linked together, and a full-scale reconstitution of a lateral collision does not permit their separation easily.

A method is presented in this paper that uses a subsystem-type test arrangement, reproducing the physical lateral shock sequence while having the two parameters separated. It then becomes possible to show the role played by different elements involved in a real-life impact:​

• impacting vehicle deformable front end part
• impacted vehicle structure at the door inner panel, where deformability plays an energy-absorbing role
• Impacted vehicle structure at the body side, where side speed is rigidity-dependent

As a result of these tests, a subsystem test procedure should take into account the impacted vehicle side structure rigidity, and use a flexible prop fixed to the body, for the impact phase with a side impactor.