Crash test dummies have been at the forefront of improving car safety since 1949, and it’s thanks to them that more and more of us are walking away from accidents without any serious injury.
The biggest leap forward in car safety came thanks to the Hybrid family of crash test dummies, developed in 1976. Hybrid III was designed to reflect the average American male who, back in the 70s, was 1,8m tall and weighed 77kg. Today’s Average American male however, has packed on 11kgs and is 2,5cm shorter too.
According to Scott Gayzick, a scientist at the Wake Forest Centre for Injury Biomechanics in the US, “There is now a distinct mismatch between people and dummies,” and the changing shape and weight of the driving population is forcing car manufacturers to rethink how they test their vehicles.
Crash test family value
But our eating habits alone are not only to blame for the disconnect between dummies and the driving population. The fact remains that the average is not representative of an entire population, let alone populations from different countries.
If one were to look at the Chinese market, for example, there has been a boom in the last decade with car sales. This is important to vehicle testing because Hybrid III is not representative of the average Chinese height and weight. “This doesn’t mean that the crash tests are meaningless,” says secretary general at the European car safety programme Euro NCAP, Dr Michiel can Ratingen. In fact, to keep up the Hybrid III has diversified with three adult sizes:
A taller male, a shorter female and a family with two children. And because these dummies are designed to be used to test head-on collisions, an array of cousins have been added to the mix to test other common types of accident. But these only test a finite number of the possible scenarios that can happen in a collision.
Crash tests Frankensteins
These crash test dummies also have another severe limitation. They’re not people – they have no vital organs, brains, bones or skin – and data is collected through recording sensors. While useful, they can’t accurately predict what will happen to a real person’s bones and organs during an accident, let alone the variations in bone density between older and younger people, from one ethnic group to the next.
To get around these limitations, researchers are now turning to simulation in order to test a wide variety of body shapes, ages and ethnicity. One of these projects is called the Global Human Body Models Consortium (GHBMC). Through creating virtual humans, tests are able to be run with models of people who are severely overweight, particularly around the abdomen.
To develop the models, scans of people are taken in lying and seated positions, and are followed up with MRI scans to build 3D representations of skeleton, muscles, internal organs and the brain. They then add mechanics and stiffness to the models to make it like a real human.
Building cars and people in virtual reality
Unlike the 77kg Hybrid III, the GHBMC has reproduced the average American male in 1mb and is working on constructing more sophisticated models that can be adjusted to simulate all ages, sizes and builds. And since cars are designed on computers, the models of both can then be subjected to a variety of accidents with millions of points of information not possible in reality.
But this doesn’t spell the end of Hybrid III and it’s extended family, the virtual models may have quality control problems – different servers might produce different results – and of course, you can’t argue with a physical test, says Gayzick. Ultimately though, the developments of virtual and real crash test dummies should make cars far safer, but they key remains that the dummy accurately represents the market it seeks to protect.