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Through a 50-year commitment to research and development in vehicle safety technologies, Renault has emerged as a benchmark in road safety. Renault is the only carmaker to offer best-in-class safety across its whole range – from Clio III to Vel Satis – with eight vehicles achieving maximum five-star ratings in the Euro NCAP crash tests.

For Renault, the objective of superior safety applies across all vehicle occupants, adults and children, in all seats. So Renault goes further than the criteria measured by Euro NCAP, fitting its rear seats with special systems to achieve the best possible passenger protection.

Renault uses actual safety data, from accidentology studies, to develop its vehicles. Its Laboratory for Accident Research, Biomechanics and Study of Human Behaviour (LAB) studies show that rear-seat passengers account for 10% (around 350 per year) of road deaths in France. Because Renault considers this figure far from negligible, it develops rear-seat passenger protection systems for small and large vehicles alike.

For many years now, Renault has been working on protection and restraint systems that factor in the actual tolerances of the human body. Renault’s programmed restraint system first appeared in 1995, on Mégane, in the form of a load limiter with pre-tensioner and belt-reel brake, to reduce the maximum pressure exerted on the thorax under impact conditions from 1000 to 600daN.

The Renault System for Restraint and Protection (SRP) was released in 1998 on Mégane and Clio II and featured controlled-deflation driver and passenger airbags and load limiters. This system reduced the maximum pressure on the thorax strap to 400daN, with seatbelt deceleration compensated by an airbag inflating progressively under body pressure to absorb the impact energy.

The SRP upgraded in 2001 on Laguna II, featuring seatbelts with 400daN load limiters plus adaptive front airbags that adjust automatically to impact force and driver position. A further upgrade came with the introduction of load limiters and pre-tensioners on the rear side seatbelts. Clio III is the only vehicle in its category to offer the degree of rear-seat passenger protection afforded by these advanced systems.

Accidentology studies show that adults seated in the rear account for 70% of road deaths and serious injuries. We also observe a high incidence of rear-seat passengers sliding under the seatbelt on impact, a phenomenon known as “submarining”. For this reason, optimization of pelvis restraint under frontal impact conditions is a priority for Renault. Clio III features special systems to counter this phenomenon, namely pyrotechnic pre-tensioners and an under-cushion structure that holds passengers against the seat and prevents them from sliding forward. In addition, the seatbelt anchor locations are designed to ensure that the belts remain properly located against the thighs and pelvis, rather than across the stomach, which is much more fragile. Renault is the only carmaker to offer rear-seat protection features of this calibre on Bsegment cars (Modus and Clio III).

Though the new protection systems are discreet enough to escape notice by passengers under normal driving conditions, they nevertheless afford excellent coupling between seat and passenger under impact. If all cars in France were similarly equipped (and if all rear passengers wore their seatbelts), then we would see a 30% reduction in the number of serious injuries and a 39% drop in the number of road deaths.

Clio III also introduces a new-concept seating system for children aged 6 to 10 in the central rear seat. The seat cushion is shorter, enabling the child to sit properly. The seatbelt buckles are farther forward and lower down, to ensure correct positioning of the strap against the pelvis and prevent submarining. And an additional belt guide above the seat back prevents neck discomfort. With the convertible child head restraint option, the strap guide is included in a special pack.

Child safety, a major issue in itself

Around 30% of rear-seat passengers involved in road accidents in Europe are children under 10. When designing safety systems with children in mind, it is important to realize that a child’s body is not just a scaled-down version of an adult body. For example, a baby’s spinal cord cannot resist a whiplash head movement under impact conditions. Then the iliac spines on a child’s pelvis are unformed, a morphological difference that brings additional vulnerability. For reasons such as these, children up till the age of 10 need special seats adapted to their anatomy. Some 60,000 children are injured in road accidents in Europe every year, often as a direct result of ill-adapted or missing safety systems. In 22% of cases, a suitable protection system would have prevented serious injury.

Children must always be strapped in their seats using systems adapted to their age. To meet this need, Renault started fitting its cars with Isofix child-seat fasteners in 1998. This standardized anchor system is necessary because a child seat or booster can only afford effective protection if it is solidly attached to the vehicle seat.

Compatibility at work

In France, 18% of road deaths and 25% of serious road injuries occur during front-to-front collisions, and in 45% of cases, there is a weight difference of more than 200kg between the cars involved. 

Part of Renault’s work on road safety concerns inter-vehicle accident compatibility, which means compensating for the adverse effects of dissimilar vehicle weights, to enable both vehicles to absorb sufficient impact energy. 

The aim is to ensure that injury risk and vehicle occupant protection are as independent as possible of vehicle weight. For example, the structure of Clio III uses new steels and other materials capable of absorbing and dissipating kinetic energy as efficiently as possible. Front, side and rear body parts are designed to crumple progressively and thereby minimize the transfer of impact energy to the vehicle occupants.  Conversely, the passenger compartment is designed to form a stiff, deformation-proof survival cell, capable of preventing the intrusion of parts from the engine compartment. The upper structure is designed to transfer impact energy via the dash side reinforcer, the front pillar and the door panels.

Scénic is 220kg heavier than Clio III. A frontal collision between these two vehicles, each travelling at 50kph, typifies about 9% of real-life accidents. In this particular case, the crash severity for the lightest car (Clio) corresponds to an impact at 60kph, a scenario that accounts for 25% of deaths and 50% of serious injuries.

Source:  Renault Presse