Modern cars have numerous safety features. From seatbelts to blind-spot monitoring to anti-lock brakes, they are designed to keep you safe when you are behind the wheel. But one of the most invisible means of keeping you safe is hiding right under your dash. Though now required by US law to be standard in all new cars since 1998, airbags are an important safety feature that were slow to catch on. Rudimentary models were installed in some cars as early as the 1970s, but didn’t become standard for over two decades.
Air Bag Inspiration: A Father’s Search For Safety After A Crash
One of the most oft repeated inspirations for the invention of air bags is an anecdote from 1952. John W. Hetrick—retired industrial engineer—was out for a drive with his wife and 7-year-old daughter when he was forced to brake hard, causing him to swerve his car and its occupants into a ditch. During the crash both him and his wife performed the instinctive gesture of throwing their arms out to prevent their child from hitting the dash, the action of which stayed in Hetrick’s mind long after they safely returned to the road and continued on their way.
With the gears turning in his head, he later that year patented a “safety cushion assembly for automotive vehicles” that used compressed air to inflate 3 airbags placed at strategic locations along the front dashboard of a vehicle. Though it was later discovered that compressed air could not inflate an airbag quickly enough during a crash to make an airbag wholly effective, Hetrick was the first to suggest a device that so closely resembles today’s airbag systems. Unfortunately, despite offering his ideas to automakers of the day, there were no takers. Hetrick’s idea was not implemented anywhere at that time.
Time for A Breakthrough: The Tiny Sensor That’s an Awfully Big Deal
It wasn’t until the development of a sensor that could accurately detect car impacts that the airbag industry as we know it today finally took off. In 1967 American mechanical engineer Allen K. Breed invented the ball-in-tube mechanism which used an electromechanical sensor involving a magnet and a steel ball to detect a car’s impact. With this new sensor and the use of sodium azide as a propellant, the airbag could be deployed within 30 milliseconds of the initial impact, far more quickly than anything using compressed air. At the same time as this major American breakthrough, Mercedes was also working simultaneously across the ocean to develop the first airbags for their cars.
Seatbelts vs. Airbags: The More Safety Devices the Merrier
Around the 1960s and 70s there was a lot of talk about passive and active safety devices. 1968 saw the requirement of all cars to have safety belts installed. By 1974, all cars needed either seatbelts or airbags. A problem with seatbelts and airbags is that they work better together, but only the airbags were passive safety devices that would work without the driver’s input. Seatbelts need passengers to actively use the device to actually have any effect during a crash. Many drivers did not use their safety belts, so the injuries sustained from airbag inflation in a crash while not wearing that seatbelt led some to erroneously believe that the airbags didn’t enhance safety during a crash. For an airbag to be most effective, it must be used in tandem with that safety belt.
Despite people’s misguided hesitations, by 1981 Mercedes offered a front airbag in their S-Class. In 1987, Porsche’s 944 Turbo was the first car to have driver and passenger side airbags as standard on the car. Front airbags became more popular in the US, with Chrysler leading the way in US car manufacturers.
Not Just For the Steering Wheel: Today’s Many Varied Airbags
Though we mostly think of airbags as coming out of the steering wheel or from the dashboard during a wreck, modern cars have many more types of airbags to keep you safe during collisions. Though cars have crumple zones built in to the front of the car that paired with your seatbelt and front airbag will often keep you safe in the event of a frontal impact, side impacts are inherently more dangerous due to that lack of crumple zone.
This led to the invention of side airbags and torso protection, which was made standard equipment on Volvos back in 1995, before regular airbags were even required in the US. Saab later introduced combined head and torso airbags in 1997. BMW pioneered the side curtain airbag in 1997, with both the 5 Series and the 7 Series having them installed as standard. Japanese and European automakers spearheaded airbag innovations while at the same time several American automakers (specifically Ford and GM) continued to lobby the US government to prevent airbags from being required on new vehicles.
The Airbag’s Legacy of Safety: Passive Protection for All Passengers
Though a number of folks are still skeptical of the safety records of both safety belts and airbags, the proof is in the statistics. According to the National Highway Traffic Safety Administration, airbags have saved over 6,000 lives just from 1990 to 2000. Proper use of seatbelts combined with the passive airbag safety devices is an easy way to make sure you and your loved ones stay as safe as possible on the road.
