In frontal impacts involving two light vehicles, two injury mechanisms are jointly involved, namely, deceleration and intrusion. Generally speaking. the objective of research aimed at improving safety in case of an accident is primarily to improve the occupants internal protection by acting on these two mechanisms‘ In this paper we will pay particular attention to giving some research orientations with the aim of taking into account the occupants safety of the antagonistic vehicle. After trying to determine the main parameters to be taken into account (mass, power/weight ratio, geometry, stiffness...) as well as some indicators. we give a few research directions for study in the framework of the test procedures' definition, in order to take into consideration the notion of aggressiveness and more widely the compatibility between the frontal structures of the light vehicles Among the paths worth exploring, we suggest working on the deformation of the obstacle which is defined in the regulatory test procedure projects. This work is supported by a literature study and our experience of impact testing against rigid or deformable fixed obstacles.