A man's world: Why are cars designed and built with just male bodies in mind?
Cars have become much safer for everyone; thanks to modern crash testing and research we have come to expect our cars to protect us whether on family road trips or the daily commute.
For decades, crash test dummies have been used by scientists and engineers to gain an understanding of the multiple ways in which collisions impact car occupants.
Strapped into car seats and propelled at speed, they are designed to measure the effect and the impact of real-life crash situations and highlight potential injury.
For car buyers, these tests give invaluable information about just how safe a car is for both driver and passengers as safety ratings are awarded by the European New Car Assessment Programme (EuroNCAP) to all new cars.
But do those ratings apply to all car occupants equally? It seems not.
The most commonly used crash test dummy has the same dimensions and mass as an average adult male from the 1970s. So, why does it matter? Surely the structure of male and female bodies is sufficiently similar to not affect the outcome of safety tests?
Women are not scaled-down men and they have different physical characteristics, such as height, weight, bone density, and muscle mass. Because cars are designed for, and tested by, models representing the "average male," the results from these tests do not accurately predict the safety risks for female occupants in a crash.
Research shows that women are 73 per cent more likely to be severely injured or die in a frontal crash than men and three times as likely to experience whiplash injuries.
The seating position can increase the risk of injury. As women tend to be shorter, they generally sit closer to the steering wheel, making them more vulnerable to lower-body injuries involving the legs, spine, and abdomen.
Despite the fact that, on average, women have a higher seatbelt usage rate than men in fatal crashes, have a lower mean body mass index, and drive newer cars, women are clearly at higher risk than men in vehicle collisions.
The safety ratings from the EuroNCAP are determined from a series of vehicle tests that are designed to represent important real-life collision scenarios that could result in injured or killed car occupants or other road users.
Male dummy from the 1970s
A number of different crash test dummies are used to represent drivers, all are based on the size and stature of an average adult male except the Hybrid III dummy, which represents a small female adult occupant.
However, this dummy, in use only since 2015, is essentially a modified version of the male dummy, which has been in use since the 1970s.
It does not in fact capture female geometry, such as the shape and form of the torso, muscle strength, spinal alignment, or the mass distribution of different body parts. It therefore does not reflect many of the physiological differences between men and women which potentially change the impact certain crash scenarios impose on women.
The crash tests performed by the EuroNCAP not only make independent information about a car’s safety available to consumers the results also influence how car manufacturers design cars.
While there is no updated representation of an average female used in car safety tests, women will miss out on the increased protection which could be afforded by changes to the overall design of a car.
And it's not just women who are missing out.
Elderly and obese drivers have high fatality rates per vehicle mile driven and research has demonstrated that elderly females and obese males suffer greater injury in crashes of equal severity than the "standard" male.
Changes on the horizon
But things are changing. Swedish engineer Astrid Linder and her team at the Sweden National Road and Transport Research Institute (VTI) are working to address this disparity by developing the first crash-test dummy prototype modeled on an average-size woman.
Their dummy is 162 cm in height and weighs about 62 kg and reflects geometrical differences between males and females including lower stiffness between the joints and less muscle.
Car manufacturers cannot protect the whole population without models representing the female part of the population as currently engineers simply don’t have enough data to design the optimum safety in vehicles.
There are gaps in the current knowledge of the risks presented to each occupant group. A more advanced and detailed female test dummy THOR-5F is due to be adopted by the EuroNCAP and will go far to providing a more complete picture of vehicle safety and increasing the level of protection for all passengers.
In order to understand the risks that are presented to each group, safety tests must reflect all types of car users; from the old to the young.
The average male cannot be the default for all car users, so more diverse crash test dummies are needed to ensure star ratings identify which cars provide the best protection for the whole car-using population.