Owing to its efficiency, reliability, and most favorable cost/efficiency ratio, the 3-point seatbelt tends to be generalized;​ in Europe, wearing seatbelts is gradually becom- ing compulsory for front occupants. Is it reasonable to go further and make the wear ing of belts compulsory at rear of vehicles, too? The answer is difficult, for:​

• Young children, who in 28 percent of the cases occupy these places, cannot be valuably protected by belts.
• Rear seat occupants may adopt most different positions;​ their number and size vary greatly according to the travel.

Wearing belts would be particularly constraining at the rear of vehicles and less efficient because they would be less accepted, not to mention the trouble created by fastening belts.

No doubt safety shall be the prior aim provided that the automotive transportation qualities will not be ruined;​ the aim of this presentation is to propose an alternative to the 3-point seatbelt, which is at least as efficient as the latter and much more comfortable. It is a passive protection system fitted into the passenger compartment. The main results of an impact testing program are also presented;​ it involved various occupants (men, women, children) adopting different postures, while ascertaining the system's efficiency. This system provides protection to rear passengers while it does not interfere with the front occupants' protection.