The Rough Road To Air Bags
THE CHANCE ENCOUNTER BETWEEN Priscilla Vansteelant and Ronald Woody II is one for the record books. Five years ago Vansteelant was driving her 1989 Chrysler LeBaron sedan near Culpeper, Virginia, when she drifted left of Rural Route 640’s center line. Coincidentally Woody was driving a 1989 LeBaron convertible in the opposite direction. The two LeBarons met corner to corner on a blind hilltop at a closing speed of seventy miles per hour. Vansteelant was wearing a seat belt but Woody was not. Both walked away with only minor injuries because each LeBaron was equipped with an air bag. The March 12, 1990, accident was the first recorded collision between two vehicles in which an air bag deployed to protect each driver.
Woody remarked to reporters shortly after the accident, “There is no doubt in my mind that air bags work. I can’t say enough about them.” He drives a car with an air bag today and is now a devout seat-belt wearer.
Describing her brush with death, Vansteelant noted, “The air bag made a quick whoosh. It’s a jolt, but not a hard jolt, like when you were a kid and jumped on a mattress.” She was ticketed for driving left of the center line. After their rendezvous the two Virginia motorists costarred in a public-safety film espousing air bags. Their mangled LeBarons are permanently enshrined at the Insurance Institute for Highway Safety’s Vehicle Research Center, in Ruckersville, Virginia.
Vansteelant, Woody, and thousands of carcrash survivors since owe their lives to John W. Hetrick, a retired industrial engineering technician. In 1953 Hetrick was issued U.S. Patent 2,649,311 for what he called a “safety cushion assembly for automotive vehicles” intended to reduce injuries during emergency braking and frontal collisions. While the Patent Office is well stocked with contraptions aimed at mitigating car-crash trauma, Hetrick’s safety cushion is the first true prototype for the modern air bags that are rapidly becoming standard equipment in all cars and light trucks sold in America.
AIR BAGS ARE DEPLOYED ONLY IN severe frontal impacts—approximately equal to or greater than a twelve-mph crash squarely into a concrete barrier, or a twenty-four-mph crash into a stopped car of similar weight. Two or more deceleration sensors located at the front of the vehicle send an electric current to the air-bag module(s). “Safing” sensors, usually located in the passenger compartment, avoid unwanted deployments. To inflate the bag, at least one collision sensor and one safing sensor must close.
The driver air-bag module, the part typically in the steering wheel, consists of an inflator assembly, a folded nylon bag, and a breakaway cover. Inside the inflator a tiny initiator—similar to the primer in an ammunition cartridge—is fired by electrical voltage from the crash sensors. The initiator ignites a propellant, usually sodium azide, which burns to produce nitrogen gas. A filtration screen cools the gas and removes cinders as the gas inflates the bag.
Inflation of a driver’s air bag to a volume of 2.3 cubic feet requires only thirty milliseconds. The driver’s forward momentum forces the nitrogen through vents back out of the air bag in another forty-five milliseconds, absorbing energy and reducing the severity of impact between the driver’s torso and the vehicle interior. The greatest protection is provided when the bag is used as a supplement to ordinary lap and shoulder belts. A passenger-side air bag is about twice as big and takes slightly longer to inflate.
Lee Iacocca, as chairman of the Chrysler Corporation, called air bags “the most important safety advancement since four-wheel brakes” in 1990, when they were finally winning wide adoption. But that advancement had taken more than three decades of engineering and research and endless political squabbling. Today’s effective yet unobtrusive air bag is a far cry from the original “safety cushion” envisioned by Hetrick in the early fifties.
Hetrick is a reserved seventy-six-year-old with thinning gray hair, trifocal spectacles, and a warm smile. He lives with his wife, Jeannette, in Newport, Pennsylvania, a small town on the Juniata River about a hundred miles outside Philadelphia, and he worked most of his life as a civilian engineering technician at military installations in Pennsylvania.
He clearly recalls the incident that inspired his invention: “In the spring of ’52, my wife, my seven-year-old daughter, Joan, and I were out for a Sunday drive in our 1948 Chrysler Windsor. About three miles outside Newport we were watching for deer bounding across the road. Suddenly there was a large rock in our path, just past the crest of a hill. I remember hitting the brakes and veering the car to the right. We went into the ditch but avoided hitting both a tree and a wooden fence. In that respect we were very lucky.
“As I applied the brakes, both my wife and I threw our hands up to keep our daughter from hitting the dashboard. There was soft mud in the ditch, so the car wasn’t damaged, and no one was hurt.
“During the ride home I couldn’t stop thinking about the accident. I asked myself, ‘Why couldn’t some object come out to stop you from striking the inside of the car?’ As soon as I got home that night I sat down at the kitchen table and drew some sketches. Each evening for the following two weeks, I’d add or subtract something from the sketches.”
HETRICK’S ACCIDENT PRO vided the motivation to invent, but his ideas were actually gathered over a period of several years. A key incident had occurred in 1944. While repairing a Navy torpedo, he saw its canvas protective cover suddenly inflate. “When the compressed air inside the torpedo was accidentally released, the canvas bag blew up and shot to the ceiling in the blink of an eye,” he remembers. After the war he commuted to an Air Force base thirty-five miles from his home. “I saw many car accidents along the way,” he recalls. “Many sheet-covered victims, many with horribly mangled faces. Reconstruction surgeons called them ‘steering wheel faces’—with good reason.”
With the help of an illustrator and a patent attorney he found in the classified pages of Popular Science magazine, he filed his disclosure on August 5, 1952, and waited for more than a year for the patent to be issued. The application process cost about $250.
Hetrick was initially surprised at the interest his air-bag patent generated. “A New Jersey insurance firm wrote to order air bags. Unfortunately I was in no position to manufacture anything. My wife corresponded with all the car companies in Detroit. Some of them replied with forms, which we filled out and sent back, but we never heard from them again.”
The air bag Hetrick invented is a simple but elegant mechanical design. Compressed air for inflation is contained in a cylindrical pressure vessel. A spring-loaded weight senses the vehicle’s deceleration. Forward motion of the weight opens a valve that allows air from the pressure vessel to inflate bags on the steering-wheel hub, atop the dashboard, on the glove-box door, and inside the front seat-backs (for rear passengers). While Hetrick’s idea was brilliant, his air bag probably wouldn’t have worked. Perfecting the idea for commercial use would take vast armies of engineers and technicians decades.
Hetrick never earned a dime from his patent, and little did he know at first that Detroit began considering air bags shortly after it was issued. In 1955 David Peter Mass chose the concept of a gas-filled air bag as the subject for his master’s thesis at the Chrysler Institute of Engineering. Like Hetrick, he got his inspiration from personal experience: a childhood accident involving his family’s car. From the back seat Hass watched his unrestrained parents fly forward into the windshield. Unfortunately Chrysler wasn’t interested in pursuing Mass’s ideas, and he was assigned to automatic-transmission design. In 1964 he was recruited by Eaton, Yale, and Towne, a diversified industrial supplier (now the Eaton Corporation), to begin air-bag research in earnest.
Ford and General Motors experimented with inflatable restraints in the late 1950s and learned just enough to realize that this was no small undertaking. Crash tests showed that there’s precious little time to deploy a protective device: within forty milliseconds of a collision’s initial contact, passengers are already leaving their seats. The “second collision”—an expression coined by an Indiana statepatrol sergeant in the late 1940s—occurs when the passengers hit the car’s interior. It’s that second collision, trailing the first one by some ninety milliseconds, that inflicts injury.
These early research efforts identified two engineering challenges: quickly, reliably, and accurately sensing a collision, and inflating the air bag in forty milliseconds or less. There were two obvious ways to inflate. One was by generating the necessary gases, the other by transferring them from a highpressure, small-volume container to a higher-volume, lower-pressure air bag. Ford researchers used rubber life rafts to clock inflation times. The results were disappointing, supporting the skeptics’ view that a forty-millisecond inflation time was impossible.
At Ford the fond hope was that new “Lifeguard” safety equipment introduced on 1956 production models would prove so popular that the development of complex, expensive air bags wouldn’t be necessary. The Lifeguard package included seat belts, a padded dash, a deeply dished steering wheel, and padded sun visors. It was a miserable failure. The buying public was more interested in power packs and continental kits. When Ford’s volume fell, executives faulted the company’s safety campaign. Air-bag investigations were shoved to a back burner.
IN THE EARLY SIXTIES DR. CARL Clark at Martin-Marietta conducted air-bag experiments aimed at protecting space-capsule passengers during landing. His NASA-sponsored research suggested that such a system might also be useful for both aircraft and ground transportation. Clark even suggested personal air bags for the elderly, to prevent hip fractures in the event of a fall.
He tried out the idea with a 160mph crash test of a grounded DC-7 airliner, sidestepping the sensing and inflation problems by using pre-inflated passenger restraints. Instrumentation failure made the results inconclusive, but the dummies with air bags did fare better than unprotected dummies, whose heads snapped off. Unfortunately Clark’s enthusiasm and research were ignored. The auto industry, the federal government, and, most important, the buying public simply weren’t interested.
In 1966 two key developments prompted Ford to resume its investigations. A new detonating valve created by the U.S. Army at the White Sands Proving Ground justified renewed gas-transfer experimentation. And researchers at Eaton successfully tested a pre-inflated air-bag system of their own design. The air-bag cause gained new momentum.
Eaton’s automotive research center had entered the safety field in 1964, looking for new products to develop. David Peter Hass—the same engineer who had outlined the concept nearly a decade earlier at Chrysler—was assigned responsibility for a multimillion-dollar air-bag feasibility study. Soon thereafter Eaton joined forces with Ford, which specified design parameters and conducted crash tests.
RALPH NADER’S BOOK UN safe at Any Speed , published in 1965, marked the dawn of the modern auto-safety era. Nader mentioned air bags only in passing while advocating a far grander concept: passive restraints. According to America’s selfappointed consumer advocate, “The seat belt should have been invented in the twenties and rendered obsolete by the early fifties, for it is only the first step toward a more rational passenger restraint system which modern technology could develop and perfect for mass production. Such a system ideally would not rely on the active participation of the passenger to take effect; it would be the superior passive safety design which would come into use only when needed, and without active participation of the occupant.”As usual, Ralph Nader was only partially correct. Air bags would eventually prove very effective at saving lives on the highway. But they would do so only with the active participation of drivers and passengers. Technology hasn’t yet rendered obsolete the simple act of buckling a lap and shoulder belt.
Nader’s diatribe only perplexed Detroit, but it energized Washington lawmakers. Congress quickly passed the National Traffic and Motor Vehicle Safety Act of 1966, establishing an agency to promulgate motor-vehicle safety standards. The laws of the land would soon force car consumers to buy safety equipment whether they wished to or not.
The Ford/Eaton air-bag prototypes relied on a conventional lap belt to prevent ejection during rollovers and to minimize injury after the air bag deflated, in multiple-impact accidents. Only the right-front seating position was extensively investigated, but the results were encouraging.
The Ford/Eaton design used nitrogen gas stored at 3,500 pounds per square inch (psi)—similar to the inflation means proposed by Hetrick. Gasgenerating explosives were avoided because of the heat and toxic gases they might produce. A nine- to ten-cubic-foot nylon bag was folded tightly around the vessel holding the gas and sealed to a diffuser tube. When triggered by a g sensor, a detonator would release the gas through the diffuser tube into the air bag. The detonator’s explosive power was roughly equivalent to that of a .22-caliber rifle shell; it inflated the air bag to approximately 2 psi.
The first round of forty-two crash tests, using first pre-inflated and then sensor-triggered air bags, showed significant progress: seat-belt loadings were reduced by 50 to 70 percent in 30-mph barrier tests; head and chest decelerations were reduced 40 to 50 percent; existing crash sensors proved fast and reliable in barrier tests; the need to quickly deflate the bags was demonstrated; and the need for an air bag for the driver was established.
Static tests showed that inflating air bags in a small car created a 160-decibel noise level—louder than a shotgun blast—and elevated air pressure inside the car by 1.12 psi over 0.014 seconds. Human volunteers at Wright-Patterson’s Aerospace Medical Research Laboratory suffered no significant injury or hearing loss. Sled tests at Holloman Air Force Base in New Mexico demonstrated that live primates could withstand 57g crash simulations when restrained by air bags but succumbed during 40 g crashes wearing conventional seat belts. A decade and a half after Hetrick’s good idea, air bags had finally proved effective in laboratory conditions.
In 1968 Ford and Eaton concluded that the feasibility of the air-bag concept had been demonstrated. Plans were laid to offer air bags in 1971 fullsize Ford and Mercury models. But then Ford’s confidence quickly waned. Toward the end of 1969 the company’s chief body engineer, Stuart Frey, reported “serious performance deficiencies” in the hardware intended for mass production. Child-size dummies with their faces too near the air bags at the time of deployment had received the equivalent of fatal injuries. The bags were slow and ineffective during angular crashes. And the instrument panel tended to deform seriously, and the windshield to break, during airbag deployment. Frey sent his engineers back to their drawing boards.
GM meanwhile worked diligently to perfect air bags during the 1960s with its own approach and objectives. There had to be considerable duplication of efforts, for the strict antitrust laws in effect at the time prevented any cooperation between companies in developing air bags for the common good. At GM the hope was for an air bag for every seating position, to offer protection in a broad range of accidents, including rollovers. But, as at Ford, the more tests they conducted, the more problems GM engineers discovered: unacceptable sound levels and shattered glass when multiple air bags were simultaneously triggered; crash dummies poorly mimicking humans, particularly in the neck area; a need for overall reliability greater than on spacecraft; the need for any air-bag design to work for passengers ranging in size from three-year-old children to ninety-fifth-percentile males; the need to redesign most of a car’s interior to accommodate the bags—redoing climate-control systems, windshield wipers, the instrument panel and glove box, the front seat, and underlying structural components.
Against these odds GM had several factors in its favor. One was the expertise of its AC Electronics aerospace division. AC had developed and manufactured the Boeing 747’s inertial navigation system, including accelerometers that could be used for crash sensing. AC’s work on hypervelocity re-entry physics was useful for the gas dynamics of bag filling. Caselessammunition development for the Army gave the division propellant experience. And its systems-analysis experience in aerospace work enabled it to create models to predict the motions of passengers and air bags during collisions.
Most important, GM had a champion strongly in favor of developing air bags. Edward N. Cole, GM’s president from 1967 to 1974, was widely regarded as the auto industry’s towering genius, an engineer willing and eager to accept the toughest technical challenges. He developed automatic transmissions and V-8 engines at Cadillac, Chevrolet’s first V-8, and, at the end of his career, the catalytic converter. His unflappable support was critical to the air-bag cause.
The government’s role in getting air bags into production cars began in earnest in July 1969, when it warned the auto industry of impending rule making. Responding to Ford’s initial enthusiasm, the Federal Highway Administrator, Francis Turner, characterized air bags as “an optimum solution in the final stages of development”—never mind the truth. A target installation date of January 1, 1972, was set. Manufacturers were unanimous in their response that this was not only unrealistic but impossible. As a result, the implementation date was delayed a year, with passive seat belts to fill in for that first year. What ensued was a political battle that raged both in Congress and in the courts for fifteen years. Not until 1984 was a final rule issued, specifying that passive restraints be phased in beginning with the 1987 model year.
THE INDUSTRY faced a host of problems, including the risk of selling the public unproven technology. The government, specifically Douglas Toms, chief of the National Highway Safety Bureau, regarded air bags as a panacea, capable of protecting all the passengers in a car in a broad range of accidents, even if they didn’t buckle their seat belts. Meanwhile the insurance industry, in league with various public-interest organizations, kept the pot boiling by suing government administrators when passiverestraint standards were inevitably delayed. The car-buying public, which suffered through two energy crises during the 1970s and a futile attempt by the government to jam interlocks down their throats (these disabled the starter until the seat belts were fastened), became less enthusiastic than ever about auto safety.
BEHIND THE SCENES, WORK continued. In 1969 Allen Breed, a New Jersey mechanical engineer, developed a reliable five-dollar crash sensor exploiting mechanisms originally developed for use in time-delay ordnance fuzes. His design, which eventually was widely adopted, has a steel ball slide within a smooth bore to act as an accelerometer during the crash sequence. After moving sufficiently far, the ball closes electrical contacts, triggering air-bag inflation. To prevent its going off over bumps and potholes, the ball is restrained by a permanent magnet, and its motion is damped by the air in the tube. Gold plating the surfaces ensures reliable electrical contact, with no corrosion, for years.
Breed was duly rewarded for his critical contributions to the air-bag cause. Breed Technologies, Inc., became the world’s leading crash-sensor supplier and a major inflator-module manufacturer. It had an estimated 1994 net income of $66 million.
Researchers at the Thiokol Chemical Corporation (later Morton-Thiokol, and now Morton International) began experiments in 1968 using solid propellants from aerospace rocket motors to inflate air bags. The goal was to eliminate the need for stored gases and thus save weight and space. Sodium azide became the propellant of choice because it generated nontoxic nitrogen gas with very low levels of contaminants, including carbon monoxide concentrations below 0.2 percent.
Morton’s creativity and tenacity eventually paid off. The company is now the dominant propellant manufacturer, with an estimated 1994 net income of $269 million. Both Morton and Breed set up highly automated manufacturing systems to meet air-bag demand at low cost. But of course the road to air-bag prosperity was littered with casualties as well. The most notable dropout was Eaton, which gave up in 1978, citing limited market potential and the threat of product-liability suits.
In the early seventies GM seized the pole position in the technological race by fitting one thousand 1973 Chevrolet Impalas with air bags for a field trial. That program served as a practice lap before the public introduction of the more sophisticated Air Cushion Restraint System (ACRS) on 10,000 full-size Oldsmobile, Buick, and Cadillac vehicles during the 1974 to 1976 model years. This was a key event in air-bag history: it marked the first time systems were offered to the buying public. Convinced it was on the right track, GM didn’t hedge its bet. Tooling was put in place to manufacture 100,000 air-bag-equipped autos a year. The price tag, to provide air bags protecting all three front-seat passengers, varied from $181 for a 1974 Buick to $300 for a 1976 Cadillac.
The GM ACRS used a reinforced energy-absorbing steering column and knee restraints built into the dash to dissipate 85 percent of the driver’s forward momentum during a collision. The steering-wheel-mounted air bag served primarily as a means of distributing loads evenly over the driver’s head and chest. The driver’s air bag was deployed by a pyrotechnic inflator, while a hybrid inflator (compressed air augmented by a pyrotechnic charge) was used on the larger passenger-side bag. Four sensors were fitted: a bumper-mounted “impact” detector containing a low-level sensor and three pendulous-mass accelerometers attached to the car body (two low-level sensors triggered at 18 g and one high-level one at 30 g).
Inflating the driver’s air bag and, generally, the passenger air bag required that a combination of two lowlevel sensors (bumper or pendulum) close simultaneously. The high-level pendulum sensor triggered an additional pyrotechnic in the passenger module for faster inflation in severe crashes. A large capacitor provided backup voltage for one hundred milliseconds in case of battery failure. An elaborate diagnostics system checked for shorted or open circuits, lack of power, and sensor failures. A complete crash-monitoring system used a separate set of sensors to record and quantify the crash sequence, to facilitate accident reconstruction. All the major components were manufactured by various GM divisions. In its day the GM ACRS was probably the most sophisticated electromechanical package ever installed on any production automobile. All modern air-bag systems evolved from its design.
But it didn’t sell. Only 10,321 cars equipped with air bags were manufactured during the three years they were offered to the public. The Wall Street Journal accused the world’s largest car manufacturer and its dealers of discouraging air-bag sales—a bizarre allegation, given GM’s huge engineering investment.
To gauge the effectiveness of the product, GM dispatched a trained investigation team to study accidents involving air-bag-equipped cars. The results were revealing. The bags reduced serious injuries to the driver by 8 to 21 percent in frontal collisions; on the passenger side they helped far less, reducing severe injuries by an estimated 16 percent and increasing the likelihood of less severe injuries—bruises, sprains, fractures—by some 34 percent. Investigators found that the injuries could often be traced to out-of-position passengers being struck by the rapidly deploying air bags.
GM’s air-bag patron, Ed Cole, commenced a well-deserved retirement in the midst of the world’s first air-bag production program. When that program ended because of the poor sales, air bags went into an eight-year hibernation as far as the buying public was concerned, while the government, the insurance lobby, and representatives of the automakers squabbled behind the scenes.
MERCEDES-BENZ, A LEAD ing proponent of automobile safety, was the first to reintroduce air bags, offering them for sale in the 1984 model year. They were optional on the driver’s side on several models and became standard equipment across the line two years later. This was a significant turning point because Mercedes insisted that air bags must play a supporting role with existing seat-belt systems. To register that notion with the public, Mercedes coined a new name for air bags—supplemental restraint systems—which soon spread throughout the auto industry.
A year later the Ford Motor Company’s president, Donald Petersen, announced that a driver’s-side air bag would be an $815 option on 1986 Ford Tempo and Mercury Topaz models. Confirming Mercedes’s point of view, Petersen declared: “The air bag is not a substitute for seat belts, which we think are the most effective accident protection system. But we do want to test customer acceptance of air bags in actual use because we believe they could prove to be a valuable safety addition to seat belts.”
GM compared the effectiveness of belts and bags in a detailed 1989 study. The conclusions were that belts alone are approximately 42 percent effective in reducing fatalities. Combining belts with inflatable restraints increases effectiveness to 47 percent for the driver and 43 percent for rightside passengers. Air bags alone, however, were deemed only 18 percent effective in reducing driver fatality and 13 percent effective on the passenger side.
AIR BAGS GRADUALLY GAINED momentum as the government’s 1984 passiverestraint edict took effect. By 1990 all new cars sold in the United States had to be equipped with either driver air bags or automatic seat belts. Chrysler’s chairman, the ebullient Lee Iacocca, starred in television commercials announcing that driver air bags were standard in every automobile manufactured by his firm. This was the same Iacocca who had suffered through the Ford Motor Company’s 1956 sales downturn j attributed to an overemphasis on safety, the same Detroit mogul who had accompanied Henry Ford II to Washington in 1970 to beg President Nixon for relief from passive-restraint regulations that were “ruining the car business.” But his television testimonials were both ; convincing and critical to the cause. After twenty years Iacocca had executed a clean 180-degree backflip on air bags.
He mustn’t be faulted though; the buying public also changed its mind overnight. Suddenly “safety was sexy,” in the words of one German expert. But more important, two interim alternatives to air bags had shown less market appeal. The simplest passiverestraint approach had the belt system anchored to the doorframe, to wrap each front-seat passenger as the door closed. Motorizing the shoulder belt was even more annoying; this scheme required occupants to complete the process manually by latching a separate lap belt. Many didn’t. Forced to choose awkward passive seat belts alone or air bags combined with comfortable seat belts, the buying public made the obvious choice, even though it cost extra.
Chrysler’s risky across-the-board commitment to commercializing air bags caught Ford, GM, and the major import brands with their pants down. The rush began to strip out passive seat belts and replace them with inflatable restraints. It was a windfall for suppliers, although some had trouble meeting the demand, especially after some early propellant-manufacturing explosions—“ unintended plant deployments,” as they were called in the trade.
In 1991 Congress ratified what was already happening in the marketplace. The Intermodal Surface Transportation Efficiency Act directed the National Highway Traffic Safety Administration (NHTSA) to amend its standard for passive protection to require air bags in all new passenger vehicles. The phase-in, covering all front-seat passengers both in cars and in light trucks, begins in 1996 and ends two years later, when 100 percent coverage will be mandatory. But requiring two air bags as standard equipment presents another problem: Air bags and rear-facing infant seats are not compatible; a deploying bag can strike the back of a baby’s head with potentially lethal force. To make amends, the NHTSA recently proposed to authorize makers to provide an on-off switch on the passenger side of vehicles lacking back seats (sports cars and pickup trucks). Switching the air bag off allows infant restraints to be secured safely on the front seat.
While strongly recommending the use of seat belts, the NHTSA does credit air bags with saving lives and moderating car-crash injuries. Four years ago the agency estimated that 2,400 lives would be spared and 29,000 moderate to serious injuries prevented by air bags during their phase-in from 1990 through 1995 (seat belts alone saved more than 5,300 lives just in 1993). The Insurance Institute for Highway Safety figures that driver deaths in frontal crashes are about 24 percent lower in cars with belts and air bags than in those with belts only. During the last decade seat-belt use has increased fivefold, from 11 percent of drivers in 1982 to 66 percent in 1993, according to the government, so the rising popularity of air bags seems to strongly encourage drivers and passengers to buckle up. Of course, mandatory federal labels and owner manuals continue to state the obvious facts that air bags don’t inflate in rollover, side, or rear-impact crashes, or in lower-speed frontal collisions, and serious injury is possible if you’re too close to one when it inflates.
Now that the bags are desirable in the public’s eyes, manufacturers are creating new opportunities to sell them. Nissan has marketed luxury limousines in Japan with rear-seat air bags for chauffeur-driven executives. And in the model year 1995 Volvo became the first automaker to offer separate air bags for side-impact protection.
By the turn of the century, air bags will be as commonplace on automobiles as power brakes and radial tires. There are already more than fifty million of them on American roads today—including two in John Hetrick’s own 1994 Pontiac Grand Prix.
