It was in the 1940s that Dr. Sheldon (no, not the one from The Big Bang Theory) had only recently opened a neurological practice in the state of California. He started to notice a very peculiar pattern amongst the patients that were being brought in to the emergency room. A very high number of these patients had suffered head injuries on account of the primitive design of the seat belts that were in use at that time. Dr. Shelden would then go on to develop a number of safety devices for the auto industry, most of which are in use even today, such as reinforced roofing, automatic door locking systems and the highly efficacious air bag. However, none amongst all of his inventions has been able to achieve as much success in saving the lives of passengers as the concept of the ‘retractable seat belt’.
Seat belts had become part of the standard equipment in vehicles in the USA by the late 1960s. It would, however, take another few decades before a substantial increase in its usage could be witnessed, largely on account of the public-education campaigns and commercials (read the Vince and Larry ads) developed by the US Department of Transportation. Almost 9 out of 10 people driving in the USA now wear seat belts, although that also means that about a quarter of a hundred million people still are highly vulnerable in the event of a car crash. The numbers are even worse in countries such as India, where about 3/4th of the driving population still hasn’t gotten used to the idea of wearing seat belts.
So what is it that makes seat belts so effective a life saving contraption in the event of a car crash? Well, apart from preventing your body from banging into hard surfaces, such as the windshield in front of you, it also prevents you from colliding with another person in the car (a human acting as a projectile can have far more disastrous consequences than one might have imagined, which is also where the idea of having seat belts for passengers in the rear comes into the picture) and reduces the force of your impact with an airbag that is already expanding at such great speeds. Given that the use of seat belts has been known to reduce fatality rates, as well as the instances of major injuries, by almost three times, seat belts are now considered as Primary Restraint Systems in any automobile.
The seat belts we see in use today have gone through a number of changes and developments since they were first put to use. From a two-point seat belt to a lap belt, to a sash, the three-point belt-in-seat (BIS) harness that we currently employ in most cars has seen quite a few predecessors. There are even four, five and six point harnesses in use, with the latter ones being employed in child seats and in racing cars. The use of pretensioners, which almost instantly tighten the seat belt in the event of a crash (as also for sudden accelerations and decelerations), and web clamps has only made the use of seat belts all the safer for the passengers using them. And there are a number of developments still taking place as well, with inflatable seat belts or seat belts with airbags being the latest in safety tech.