PRIORITIES FOR EU MOTOR VEHICLE SAFETY DESIGN

provide greater compatibility, it is necessary to overcome the problems of poor structural
interaction between cars when they impact.
Even where intrusion is prevented and the restraint systems work well, there is still a high
likelihood that the occupants’ knees will impact the facia. Until the introduction of EuroNCAP,
little or no attention had been paid to the safety of the knee impact area, other than at the
specific locations where the dummies’ knees impact. Significant hazards continue to exist for
the knees themselves and for the upper legs and hip joints.
Loading of the feet and ankles by the footwell and pedals is inevitable in frontal impacts.
Although injuries below the knee are rarely life-threatening, disabling injuries often result.
Improvements to dummies, biomechanical requirements and the cars themselves are all
required.
In side impacts, the struck side occupant is intimately involved in the impact itself. Contact
with the car’s interior is difficult to prevent so improvements rely on improving the nature of
the intrusion, the provision of padding and of side airbags. Although head protection is a
priority, the current European side impact test does little to address the risk of injury to the
head. The introduction of a pole test would help and it could also help to guide car design, so
that protection, for the whole body, in impacts with trees and posts could be improved.
The continuing need to improve protection in cars puts increasing demands on the
capabilities of test dummies and the biomechanical knowledge necessary to set
performance limits. There is an ongoing need for research in these areas to provide
information for the future.
When the European offset deformable frontal impact test was being developed, airbags
were rare in European cars. The overwhelming need was for a test to address the problem
of intrusion, with the car having a deceleration pulse similar to that experienced in a car-tocar
impact. With the almost universal fitting of frontal protection airbags and the increased
fitting of seat belt pre-tensioners and load limiters, it is becoming increasingly important to
avoid restraint characteristics being optimised for a single impact type. The offset
deformable barrier impact is a relatively low deceleration event and a higher deceleration
impact is required to complement it. With road accidents generating a wide range of
deceleration pulses, testing cars with both a low deceleration and a high deceleration pulse
encourage a better compromise of restraint characteristics. For this purpose, the introduction
of a full width barrier impact for Europe is a priority. Such a test could be based on the US
NCAP test and it might be developed into a test for compatibility (Edwards et al, 2000).
(a) Front and side impact - review of EU Directives
When the European frontal and side impact Directives were introduced there was a specific
requirement for them to be reviewed. This review was to cover certain specifications for the
tests and their criteria. Subsequently, the European Commission requested that certain
additional aspects be included in the review.
Frontal impact
Impact Speed
The accident data used to inform the research behind the Directive showed that an impact
speed equivalent to a car-to-car impact at around 55 km/h, was required to address around
50% of the fatal and serious accident casualties. This equates to a test speed of around 65
km/h. However, because of concern about the ability of manufacturers to build cars which
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