Driving or riding in a car is the most dangerous thing you’ll probably do all day, but it’s much safer than it used to be. In 2015, for every 100 million miles driven, only 1.12 people died. Compare that to 2.08 in 1990, 3.18 in 1981, and 5.04 in 1969. 1921 saw 24.09 deaths per 100 million miles.
How is safety improving? The major factors are a combination of high technology and brute mechanics.
The steel that makes up the skeletons of our cars has become much stronger over the last two decades. Around the turn of the millennium, automotive steel had a tensile strength of about 500 megapascals. Now, that number is around 1,500. To put that into perspective, you could hang 100 tons on an inch-wide strip of today’s steel without tearing it in half. That strength directly equates to more protection for drivers and passengers.
Mixed Material Crumple Zones
In the middle of last century, cars were built to be heavy and stiff. The car could take an impact, but the force was delivered directly to the occupants. In 1959, Mercedes-Benz introduced the 220, the first production car with crumple zones. In a crash, it would deform in such a way as to absorb the energy and protect the occupants. The concept has spread over time to all cars. Today’s vehicles take it to the extreme by combining aluminum, carbon fiber, various strengths of steel, and other materials to collapse in very controlled and predictable ways. The car will be trashed, but the people inside will be able to walk away.
The National Highway Traffic Safety Administration started crash testing cars in 1979. Since then, the tests have evolved from ramming cars filled with dummies into barriers and each other to advanced virtual simulations. Engineers can punish digital prototypes in every way before ever building a single one. This reduces the cost and increases the thoroughness of safety testing before a production model ever gets to the NHTSA.
Image via Flickr by digitizedchaos
Belts and Air Bags
Living people reminisce about the old days when cars maybe had lap belts and kids would commonly bounce around unrestrained in the back of the station wagon. Many people never survived that era to reminisce about it. Not only are three-point belts compulsory now, but air bags continue to improve in complexity. Side curtains, knee bags, and inflating seat belts respond to the severity of the impact by inflating with the appropriate pressure.
The best way to survive a car crash is to never have one. The modern car has a starship level of sensory and computing power. Cameras, radar, and lidar combine to keep cars in their lanes and from bouncing off each other. They sense pedestrians and can tell if the driver is falling asleep. Automakers are now competing to create cars that are completely autonomous.
As cars become tougher to crash and crashes become easier to survive, our biggest risk will be our own lack of attention. Soon, we’ll be free to completely zone out and let the car do the driving.
Image via Flickr by jurvetson