The deadliest year in automotive history was 1972. There were 54,589 driving-related fatalities in the United States that year, according to the National Highway Traffic Safety Administration. By that time, safety innovations such as collapsible steering-wheel columns had ensured that motorists were no longer impaled in front-end collisions, and laminated safety glass spared them decapitation, but the most important safety feature of all — the three-point seat belt — would not become federally mandated until 1974.

Since the 1970s, driving fatalities have steadily dropped, falling to 33,808 in 2009. Even more impressive is the decrease in the rate of fatalities relative to the overall population: In 1966, 26 people out of 100,000 died in car crashes, compared with 11 out of 100,000 in 2009. Seat belts aren't the only reason for the encouraging statistics, though. Here we highlight a handful of the most important automotive safety innovations and how they are evolving to protect motorists better.

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Seat Belts

Click to enlarge pictureNils Bohlin, 1959 (© Volvo Cars of North America)

Volvo engineer Nils Bohlin (above) is credited with developing the three-point seat belt, first offered as standard equipment in the 1959 Volvo 122.

There's no question that three-point seat belts, the kind that strap over the shoulder and across the lap, save more lives than any other automotive safety device. "They keep occupants in a position where they are safest, and prevent ejection [in a collision]," says Gabriel Shenhar, senior auto test engineer at Consumer Reports. If all passenger-vehicle occupants 5 and older had worn seat belts in 2009, 16,401 lives could have been saved, according to NHTSA.

Volvo engineer Nils Bohlin is credited with inventing the three-point seat belt as we know it today. The Swedes began outfitting their cars with them in 1959. Various lap and shoulder belts had existed before then, in both cars and airplanes, but it wasn't until 1974 that three-point belts were mandated in the U.S. In 1981, Mercedes-Benz outfitted its S-Class cars with pyrotechnic pretensioners — not to be confused with the ubiquitous mechanical tensioners — that instantly tighten the belt against the body when a crash seems imminent. Ford is the latest innovator: It offers inflatable belts as a rear-seat option on its 2011 Explorer. They minimize injury by distributing crash forces over a greater area of the torso.

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Electronic Stability Control

Click to enlarge picture1995 Mercedes-Benz S600 (© Mercedes-Benz USA)

Electronic stability control, first introduced on the 1995 Mercedes-Benz S-Class, evolved from traction control, and helps to avert a crash by detecting and minimizing skids.

Following safety belts in importance is electronic stability control, Shenhar says. That's because devices such as airbags and safety cells make a difference only once a collision happens, whereas ESC helps to avert a crash altogether. By detecting and minimizing skids, ESC reduces the risk of fatal multiple-vehicle crashes by 32 percent and fatal single-vehicle crashes by 56 percent, according to the Insurance Institute for Highway Safety. That's huge, says Joe Nolan, head of the IIHS Vehicle Research Center.

German parts supplier Bosch developed electronic stability control in the 1990s. The first production car to use it was the 1995 Mercedes S-Class. Now ESC comes standard on many vehicles, and beginning with the 2012 model year, it will be a federally mandated requirement on all passenger vehicles.

ESC uses sensors to detect the intended path of the vehicle and determine whether it's starting to skid. The system can selectively brake one or multiple wheels to keep the vehicle on course. Some systems also reduce engine torque to help stabilize the vehicle. ESC is particularly helpful for SUVS prone to rollover. It evolved from traction control, which prevents wheel spin, but traction control doesn't help steer a vehicle back on course like ESC does.

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