Behind smashing cars for safety

From the early days devoid of seat-belts and laminated windshields, car safety has come a long way. Now, cutting-edge advancements in crash testing are paving the way for even safer rides

Imagine hurtling down a highway in a car, the wind whipping through your hair, and a sense of freedom washing over you. But this seemingly idyllic picture can turn tragic in the blink of an eye in case of an accident — because you are hurtling down that highway, essentially, in a metal box.

Still, we buckle up with ease, confident in our car’s ability to shield us in case of a mishap. According to a 2023 survey —commissioned by Skoda Auto India — the top two features influencing car purchase decisions in the country were crash ratings and the number of airbags. Carmakers, including Tata Motors most recently, are increasingly talking up their vehicles’ 5-star ratings from Global New Car Assessment Programme (GNCAP) to market them, even as India has launched its own crash testing programme— Bharat NCAP.

Advancements in car safety standards, driven by rigorous scientific testing and advancements, are constantly working to tip the scales in favour of human life. Yet the story begins with the rudimentary: Early automobiles lacked basic safety features and it wasn’t until the 1930s that laminated glass windshields were introduced. Year 1959 saw the development of the three-point seat-belt by Nils Bohlin, an engineer at Volvo; it helped hold the waist, as well as torso in place during a collision. Slowly over the decades, now ubiquitous collapsible steering columns, airbags, soft cabins, anti-lock braking system, and electronic stability control were introduced.  

And now strap up for the science of smash. In car crash testing , physics takes centre stage in setting up and interpreting crash tests. In every crash, a car will decelerate from a certain speed to zero, and controlling what happens in between determines survival of the occupants. It is important in a crash to keep the passenger compartment intact and ensure that the occupants don’t turn into human projectiles (hence, the safety belts).  But also, the force that we experience in a crash is dependent on how long the entire incident takes, aka Newton’s second law of motion: F=ma (force=mass x acceleration). Acceleration (deceleration in the case of a crash) is nothing but the change of velocity over time (Δv/t). In a crash, while the “m” remains a constant, there is little control over “Δv”. So, what carmakers try to lengthen is “t”. The longer the crash takes to complete, the less the force.  And to exploit this physics trick, oddly enough, they manufacture cars that are designed to get wrecked. Early car manufactures used to make the outer shell of their vehicle sturdy, but then the transfer of force on the occupants was immediate and immense in case of a crash because the shell didn’t crumple.

Hence, designing vehicles to absorb and dissipate energy safely is critical, and for this, carmakers keep crumple zones — intentionally weak areas that deform upon impact, reducing the force transmitted to occupants.  And besides frame rails, suspension, wheels, and airbags help extend the time of crash and transfer of force. It is also crucial to highlight the importance of crash test dummies, which are packed with sensors and measuring devices. These dummies are designed to mimic the human body’s biomechanics, including the distribution of weight, skeletal structure, and organ placement. Sensors embedded within the dummies record data on acceleration, deceleration, and head and chest movement during the impact. 

 Advancements in computer modelling and simulation are allowing engineers to virtually replicate crash scenarios with even greater accuracy. Also, the development of new, lighter, and stronger materials such as high-strength steel and carbon fibre composites is enabling carmarkers to design vehicles that are lighter yet offer superior crash protection.

Advanced driver-assistance systems, which include features like lane departure warning, automatic emergency braking, and blind-spot monitoring, are already making inroads into preventing accidents. The next step could be autonomous vehicles, connected vehicles, biometric monitoring (monitoring driver’s vital signs to detect fatigue or impairment), and predictive algorithms (anticipating driver’s behaviour to prevent accidents).

And as we navigate the ever-evolving landscape of car safety, with exciting technological advancements, the future promises a world where driving is both exhilarating and highly safe. Still, buckle up!