Escape: Because Accidents Happen: Car Crash

PBS Airdate: February 16, 1999
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ANNOUNCER: Tonight on NOVA. The pioneers of auto engineering. For decades, they have smashed, crushed, and flipped cars to come up with better ways to escape, "Because Accidents Happen." Are accidents like this one survivable? In the age of crumple zones and crash test dummies, how safe are cars today? Fasten your seatbelts for "Car Crash."

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And by the Corporation for Public Broadcasting and viewers and like you.

EMERGENCY WORKER: How many do you need? How many do you need, Larry?

NARRATOR: Every day, more than 100 people die in car accidents. This one is in Memphis, Tennessee.

EMERGENCY WORKER: I got one unit that's going to take this child out of here.

OTHER EMERGENCY WORKER: Is she related to this?

NARRATOR: In one dreadful moment, three lives have been shattered. Two of these victims will not survive the trip to the hospital. In the last 100 years, more Americans have died in car crashes than in all the wars the United States has ever fought. Is there a way to make these devastating accidents survivable? This is Germany's infamous highway system, the autobahn. For long stretches, there is no speed limit. Some cars cruise at 100 miles an hour, and faster. Occasionally, German police cameras monitor the roads. Most of the time, traffic flows in predictable patterns. But recently, the cameras recorded a shocking event. As shown on this small screen in the lower right, a Mercedes in the oncoming lane is about to round the far corner, traveling almost 150 miles an hour. Playing back the tape, the police were able to see exactly what happened. The car was going too fast to make the turn. It grazed the guard rail on the right, and the driver lost control. After sliding 400 feet upside down, the car comes to a stop on the embankment, and the removable top flies off. Clearly, a horrifying accident, but what happens next is almost unbelievable. The driver climbs out - not only alive, but uninjured! A lucky man, certainly, but he also owes a large debt of gratitude to modern engineering.

INGO KALLINA: The driver in this car was very lucky because he survived a very severe accident with a special safety feature which is in this model. As you can see, it's a rollover bar, and this rollover bar is very stiff and helps to guarantee a certain survival space.

NARRATOR: As the car tilts, sensors trigger the rollover to pop up, creating a space between the driver's head and the pavement. Wearing a seatbelt is crucial to keep the occupant inside. Before the rollover bar was introduced in 1986, this kind of accident was unsurvivable. In the last 30 years, science and engineering have helped created much safer cars. Today, no new model hits the showroom without being rammed into walls, barriers, and other automobiles - to comply with international standards of safety. But it wasn't always this way. Automobile safety came slowly, and at the expense of millions of lives. This is a 1929 Chevrolet, crash tested using today's standards.

JOEL W. EASTMAN: Cars of that era were rickety affairs. They were sheet metal nailed and screwed onto wooden frames, and so they were very insubstantial. And when they got into a serious crash, they pretty much disintegrated.

NARRATOR: Survival in one of these "motorized coffins" was due mostly to luck, and the fact that cars were slow and scarce. The automobile age began in Germany. Powered by a combustion engine, the first car was built by Karl Benz in 1886. For years, the automobile was considered a toy in Europe, meant only for the very rich. It was an entirely different story in America. Soon after the turn of the century, low-cost automobiles went on the market and Americans bought them in staggering numbers -even if the roads weren't always ready for them! As the number of cars increased, so did accidents. By the early 1920s, more than half a million people had died in collisions. Yet, nobody blamed the automobile. Accidents were considered an act of God - or, a bad driver.

JOEL W. EASTMAN: It was obvious to blame the driver, the human being rather than the inanimate object. And so, the automobile industry accepted that, and therefore assumed that they had no responsibility for designing cars to be involved in accidents.

NARRATOR: Auto makers avoided the topic of car safety. Sales could be hurt if customers began to think of cars as dangerous machines. There was, however, one aspect of car design so lethal everyone recognized the need to change it - plate glass windows. A minor collision, even a small rock tossed up by a passing vehicle could shatter a windshield, sending razor-sharp shards of glass inside. In 1910, a laboratory accident would lead to a major advance in glass safety when Edouard Benedictus, a French chemist, knocked a flask on the floor. To his amazement, the bottle broke, but didn't shatter, because it was coated with nitrocellulose which had dried out, leaving an adhesive film on the inside. Benedictus didn't think much about the incident until he read of an auto accident in which a young girl's face was disfigured by flying glass. Moved by the reports, he went back to his lab. The result was a sheet of celluloid adhesive between two pieces of glass. Bonded together, they made one clear pane, the middle layer holding the lethal pieces in place. An improved form was first used in gas masks during World War I. But it took 16 years and an accident to get safety glass used in cars.

JOEL W. EASTMAN: When Henry Ford was designing the Model A, one of his engineers was injured by flying glass from an accident. And he and Edsel Ford decided to offer it in all of the new model A's, all of the Ford models.

NARRATOR: Safety glass was considered such an important advance, car companies even advertised it.

ADVERTISEMENT NARRATOR: Ah-ha! The two-plate safety glass turns back even the pitcher's bullet delivery. True, the glass cracked, but it did not shatter and fly like ordinary glass. Make a note of that, too, in choosing your next car.

NARRATOR: Used in front windshields for almost 40 years, safety glass was an improvement - although far from perfect. This, called the "glass necklace," was the unforeseen consequence of safety glass - graphically described in this film from the 1960s.

60s FILM NARRATOR: At impacts of from about 15 miles per hour and up, the glass will break out in a circular hole where your head strikes it. The edges of the hole flex, your head goes on through. The glass bubble retracts with a collaring effect that entraps your head. When the reaction hurls you back, the flexible perimeter of the hole becomes a jagged weapon of lethal intensity.

NARRATOR: The glass necklace caused serious lacerations of the neck and head, sometimes even decapitation. A glass more resistant to breakage was needed, but it couldn't be made so hard that an impact would cause serious neck and brain injuries. The answer was to replace the adhesive with a middle layer of plastic that would stretch but not break. But in most cars, glass-plastic is only installed in the front windshield, increasing the danger of ejection in side impact accidents. By the mid 1920s, there were 22 million cars on American roads. The initial demand for automobiles had been satisfied and sales were in a slump. To spur the market, General Motors instituted the annual model change.

JOEL W. EASTMAN: The annual model change was invented by General Motors as a way to get people to replace their cars sooner by basically making them obsolete. And it was wonderful. It was a wonderful gimmick which did increase sales and brought great profits, and the public loved it. But it had a negative impact on safety. Styling was where the resources were put. It's where the time and the investment was. And safety took a back seat.

NARRATOR: Dazzled by the new styles, most of the car-buying public ignored the carnage on the roads. One accident at a time, cars were taking tens of thousands of lives every year and injuring millions. There was one Detroit physician fully aware of the problem. Plastic surgeon Claire Straith spent most of his time repairing the faces of crash victims.

JOEL W. EASTMAN: Claire Straith was the first hero of the auto safety movement. He was the first to recognize that it was automobiles that injured people. An accident was just the event, but it was the collision between the passengers and the inside of the car that caused the injuries.

NARRATOR: Even in minor accidents, serious injuries would result when the human body met up with the car's interior. Protruding knobs could rupture an eye or sever a nose. Rock-hard dashboards fractured skulls and caused debilitating, crushing injuries. Claire Straith's granddaughter, Janet Straith Husband.

JANET STRAITH HUSBAND: He would have gotten in this car and first noticed this rearview mirror with its glass across the front, sharp edges up here. He would have then gone to the dash in the front of the car and seen its hard surface. And then, he would have attributed the steering wheel to crushing chest injuries, and actually, in some cases, impalement on the metal post that supports the driver's wheel.

NARRATOR: Dr. Straith came up with a simple idea that could prevent such horrible injuries.

JANET STRAITH HUSBAND: It was just a foam rubber pad. My father has kept this all these years because he remembers driving around with it in his cars. It was placed on the dash, attached with two little screws. It would protect the occupants against the knobs and the gauges and the glass. And it was soft, but yet firm enough to provide some protection for the occupants in the car.

NARRATOR: Claire Straith designed numerous pads to fit all different makes and models of cars, and tried to market his invention. But it was never a commercial success.

JANET STRAITH HUSBAND: He even talked to Walter Chrysler and Preston Tucker and tried to convince them of the design changes that were necessary to protect patients, and his patients and passengers in the automobiles.

NARRATOR: The 1937 Dodge was a direct result of Claire Straith's talk with Walter Chrysler. It had a safety smooth dashboard with knobs that were recessed. The dash was raised to prevent knee injuries, and the front seat back was padded to protect passengers in the rear. The 1937 Dodge was an improvement, but it had little influence on the auto industry as a whole. Safety would not be its focus for many years.

JOEL W. EASTMAN: The auto companies didn't have safety departments the way they do today. There was no basic scientific research. The fundamental work in this area was due to the efforts of one man, Hugh DeHaven, who for the first 20 years, financed his own research into this new and very important area.

NARRATOR: Hugh DeHaven's interest in safety began with a plane crash during World War I. He was engaged in a practice dogfight and both planes went down. The other pilot walked away, but DeHaven spent months in the hospital wondering why he alone was so badly injured. That question became DeHaven's life's work, and that of his friend and colleague, Colonel John Stapp.

COL. JOHN PAUL STAPP, M.D.: Hugh DeHaven invented the art and science of crash investigation. And he was a relentless fanatic whose gospel was, "These are not acts of God, they are failures of machinery and negligence and failures of people."

CBS DOCUMENTARY: CBS Television brings you the search . . .

NARRATOR: In 1954, more than 35 years after his plane crash, a documentary about DeHaven's work at Cornell University aired on CBS.

CBS DOCUMENTARY: This is the American Road. This is where 35,000 of you have a rendezvous with death every year.

NARRATOR: The scientists at Cornell studied the forces that injure the human body. To obtain measurements, they bounced plastic heads on dashboards and dropped tin men onto knobs. They even studied some human oddities, like the story of Louis Zito, who lost his balance while working on top of this smokestack and fell 15 stories down.

LOUIS ZITO: I think it was just plain luck.

NARRATOR: Luck, certainly, but science had a lot to do with Zito's amazing survival. Hugh DeHaven analyzed the plunge.

HUGH DEHAVEN: In this case, Mr. Zito, who had fallen from the stack here, fell a distance of almost 150 feet and achieved a speed of approximately 60 miles per hour, 62 miles per hour when he hit the ground.

NARRATOR: At that speed, Zito should have died on impact. What interested DeHaven was why he didn't.

HUGH DEHAVEN: Well, he hit a structure that was not solid concrete, luckily, and the rubble where he hit acted as an energy-absorbing agent. And as the force was well distributed on his body, there was no localized force which caused any injury.

NARRATOR: Zito's survival proved that even severe impact forces can be reduced with padding. But that kind? And how much? To test different materials, DeHaven's team used the most fragile object they could think of (an egg), and dropped it 15 feet down. The materials developed at Cornell would eventually find their way into automobiles. But DeHaven knew that padding wouldn't solve all the problems. And he proved it with some of the earliest crash tests on record.

WALTER CRONKITE: You're going to be able to see for the first time what happens to people in a car like this when this powerful force meets an immovable object.

NARRATOR: With crash tests, they would prove the central foundation of DeHaven's work, that for every accident, there are really two collisions. The first one occurs when the car crashes into an object.

WALTER CRONKITE: Now, the same crash in slow motion. Watch the little fellow in the rear.

NARRATOR: The second one, when unrestrained occupants inside the car collide with the dashboard, windshield, or even the back seat.

WALTER CRONKITE: He's folded up like an accordion almost, isn't he?

MAN: Yes. You find them in weird positions after a crash.

WALTER CRONKITE: You think he might have survived?

MAN: I doubt it. It looks pretty bad.

NARRATOR: It's the second collision that kills and injures, and Hugh DeHaven knew the best way to prevent it: seatbelts.

WALTER CRONKITE: Here's the same crash in slow motion with the dummies strapped in this time. Again, watch that little fellow in the back seat.

NARRATOR: The occupant is safely held in place, riding down the impact forces. As a result of Hugh DeHaven's studies and his relentless advocacy of seatbelts, auto makers began to offer them in cars in 1955 - not as standard equipment, but as an option. Called lap belts, or two-point belts because they attached to the car frame at two points, they were an important improvement in safety. But they weren't perfect. Head injuries, while less severe, still occurred. Spinal injuries were possible. And sometimes, when the belt was placed too far above the hips, serious abdominal injuries could result. In the 1950s, aware of the problem with lap belts, Volvo tried a diagonal belt that went across the chest. But it, too, had some fatal flaws. Retired safety engineer, Nils Bohlin.

NILS BOHLIN: This diagonal belt has two important shortcomings. First, it will cause submarining due to the fact that that strap is located far above the center of gravity, so at the crash, the body will move down, will try to sneak out of the strap. And the belt will dig into your neck, and cause neck injuries, and also decapitation of your head.

NARRATOR: Nils Bohlin would come up with a solution, simple, but very effective. He demonstrates using the same prop that DeHaven used some years earlier—first, without a belt.

NILS BOHLIN: The human being is as fragile as an egg. So, let's see now what happens with the egg in the crash. We are ready to go? And now, I would like to show how to save the egg from injuries in the crash. I picked the happy egg because he knows he is going to be restrained in a three-point lap-shoulder belt.

NARRATOR: The three-point lap-shoulder belt worked because it restrained the two strongest parts of the body, the hips and the chest, with a single belt that was anchored by three connections to the car frame.

NILS BOHLIN: One, two, three.

NARRATOR: Nils Bohlin holds the patent for the single most effective safety device in any vehicle. First installed in the 1959 Volvo, it took more than a decade for three-point seatbelts to be required in American cars. That same year, Bela Berenyi, an engineer at Mercedes, came up with a safety concept that would completely change how cars were designed and built. Before Berenyi, people believed the more rigid the body, the safer the car. But such construction was deadly to passengers because all the impact forces went straight inside the vehicle.

INGO KALLINA: Berenyi re-engineered and he reconsidered the whole issue. And he said, "Well, if we provide crumple zones together with a very rigid passenger cell, this would prevent injuries and fatalities.

NARRATOR: Bela Berenyi recognized that if the front end and back end were built to crumple, most of the impact forces would be absorbed by the outside of the car before they reached the occupants. And, if the occupant area were surrounded by a rigid frame, it could minimize intrusion from the crumpling members.

INGO KALLINA: I think it was a revolution, because now, we started to re-engineer the car completely.

NARRATOR: This is Berenyi's concept in action. The damage to the car is severe, but the passenger space remains intact. The secret to this design lies deep within the car frame. Marked in red, the skeletal members are carefully designed and made of special materials that crumple in predictable ways.

INGO KALLINA: This cross member tightens together, links the two front members, and the energy is absorbed while this crumple zone is deforming. And the energy is deformed outside of the passenger compartment and there is no intrusion in the passenger cell at all. And you see this car has substantial damage, and if you look here, it has been pushed rearward. The front end is almost damaged to the half. But I'm really happy with this damage because it relates to energy dissipation, and as long as you crumple in the front end, you do not crumple in the interior space. And that's what protects the occupants.

NARRATOR: First introduced in 1959, crumple zones with rigid cabs are now the standard in every car made throughout the world—although some cars perform better than others. The only way to determine whether a car meets safety standards is to crash it, and then see what injuries the occupant has sustained. That is where anthropometric dummies come in. At about $100,000 each, dummies are as expensive as they are technically complex. Still, scientists crash, smash, and abuse them in hundreds of different ways. Each body part is made separately and designed to be as close to human as possible. Plastic skin is poured into a mold. This one will become a knee. An inner layer of flesh is extruded into the mold as well. All the body parts weigh the same as they would in a comparably-sized person. And the skin is wrapped around steel bones with joints that move smoothly.

STEVE GOLDNER: They look human to make them respond to a crash the same way the human would. The ribs flex in the same way human ribs would do if a person were to hit the steering wheel. The only difference is, the human ribs are going to break, and the dummy ribs are going to spring back. In the case of the head, it's been improved so that when you smack that head into a windshield, you're going to get the same shock pulse as you would if you had a person in there.

NARRATOR: Every car maker has a large collection of dummies - full-sized males, small females, even different sized children. For every crash test, they are outfitted with dozens of sensors. Wires connected to various parts of the dummies feed crash-impact data into waiting computers. Small foils can be attached, that change color when pressure is applied. And by matching the color, the severity of facial bone fracture can be determined. Chest and rib injury can be detected by special sensors and then graphed on computers. Everywhere a human can be injured is measured, from neck stress to ankle flexion. Dummies can't feel our pain. But they can do a good job of measuring it, repeatedly and reliably. It took almost half a century to create today's dummies. In the 1950s, they weren't much more than mannequins. One of the pioneering scientists in dummy development was Colonel John Stapp. An Air Force doctor, Stapp was willing to undergo punishing speeds, and then suffer wrenching deceleration to gather the first crude measurements of the effect of crash forces on human beings. His work was initially for aeronautic research, but it had universal applications.

COL. JOHN PAUL STAPP, M.D.: I was operating under military orders, but with everybody in the field's full knowledge that anything that we discovered about human tolerance would set standards of protection for any kind of transportation vehicle.

NARRATOR: Some tests were just too dangerous even for Stapp. For those, he used cadavers and anesthetized animals. The animal experiments would never be done today, but they did save lives.

COL. JOHN PAUL STAPP, M.D.: For the Ford Company, when they decided to use malleable spokes in the steering wheel, we did a hog for them while their engineers witnessed the - A 1,500 frame per second picture shows the rim of that steering wheel going against the abdomen and pushing it all the way to the spine, it looked like.

NARRATOR: Ford never did produce that steering wheel. With the information he gathered, Colonel Stapp went on to write the first standards for anthropometric dummies, making animal experiments and human volunteers unnecessary.

COL. JOHN PAUL STAPP, M.D.: You can't take a human and do 1,000 experiments on him in six or eight weeks in order to arrive at some conclusion you want about some part of the automobile. And with the dummy, they get everything but the cry of "Ouch," or a subjective report out of the dummy.

NARRATOR: But in the 1950s, safety still took a back seat to style. Cars were becoming bigger and more powerful. Speeding was such a problem, actor James Dean was asked to film a promotional spot.

JAMES DEAN: Take it easy driving. The life you might save might be mine.

NARRATOR: A few weeks later, Dean died on a California road. While the death rate soared, one accident in 1951 would inspire a safety idea so revolutionary that it took almost 30 years to show up in an automobile. On a ride with his family, John Hetrick swerved to avoid a rock and landed into a ditch.

JOHN HETRICK: I guess, simultaneously, instantly, we both extended our hands to keep our daughter from hitting the dash. That's when I realized there was no such thing as protection in a car.

NARRATOR: On the way home, Hetrick thought there should be something to stop people from hitting the dash or the windshield in a collision.

JOHN HETRICK: I guess first, I thought, 'Well, why not have like a sponge-like material?' Then, I thought, 'No, that wouldn't work.' So I thought, 'You'd need something better than that.'

NARRATOR: He thought of a cushion, a cloth cushion that would fill with air quickly when an accident occurred.

JOHN HETRICK: I started to sketch an air cushion. Now, the air cushion, I thought, 'Well, it has to be inflated by some means.' And that's when I thought it, when I was in the Navy.

NARRATOR: Almost a decade earlier, Hetrick worked in a Navy torpedo maintenance shop. Torpedoes carried a charge of highly compressed air. One day, an unusual event occurred. The torpedo he was working on was covered with a canvas . . .

JOHN HETRICK: And all at once, air was accidentally released. And that quick, it shot up into the air, quicker than you could blink an eye.

NARRATOR: Inspired by a torpedo canvas, Hetrick's airbag was mechanical. Triggered by springs, the bag was filled by compressed air. In 1952, John Hetrick was granted the first patent for an airbag. Shortly after, he wrote to car makers and insurance companies, trying to market his new invention. All but one letter went unanswered.

JOHN HETRICK: One company wrote back and said that they were not interested in it because people were mostly interested in fancy radios and fancy cars. And I think at the time, they had these fancy fenders. But they were not interested in safety.

NARRATOR: They wouldn't be interested in airbags for years to come. But there was one car company that tried to break the mold. In 1956, Ford introduced Detroit's first real effort at building a safer car.

1956 FORD AD: Meet one of the busiest men in town. He sells '56 Fords.

FORD SALESMAN IN AD: And that's not all. In addition, to Fords I sell safety, like this new "Life Guard" steering wheel, it acts as a cushion on impact.

NARRATOR: Ford's so-called "Life Guard" design also included a padded dashboard and sun visors, seatbelts, and safety door latches. And the company spent millions of dollars promoting it. The only problem was, nobody wanted to buy it.

JOEL W. EASTMAN: Ironically, the '56 Ford set back the progress of auto safety because the myth grew up in the industry that safety didn't sell, and so the industry put all of its emphasis on styling and performance. When in reality, it wasn't the safety, it was just the competition between Ford and Chevrolet. Chevrolet did a better job of styling and promoting that year than Ford did.

NARRATOR: Styling sold cars. And in 1960, this car captured the public's attention. The new, sporty Chevy Corvair was exciting, and an instant hit.

CORVAIR AD: If you're like most people who are interested in the Corvair, you want to know what it can do in action, out on the road.

NARRATOR: Six years later, the Corvair shook the auto industry to its core, thanks to a young lawyer named Ralph Nader.

RALPH NADER: If General Motors wishes to know why I spent an inordinate amount of time on the Corvair, it is because the Corvair is an inordinately dangerous vehicle.

NARRATOR: Nader's book, Unsafe at Any Speed, exposed many flaws in the Corvair's design, including the placement of the engine in the back, which created a rear wheel bias that could cause the Corvair to go out of control in a turn and flip over.

JOEL W. EASTMAN: The Nader incident was a very significant turning point because number one, it opened up peoples' eyes to the fact that cars were dangerous, they needed to be improved. And number two, it almost guaranteed that the Federal Government was going to regulate the auto industry.

NARRATOR: In 1966, President Johnson created the National Highway Safety Transportation Agency that would set standards of safety for all car makers to meet.

JOEL W. EASTMAN: From this point on, auto safety was mandatory. It was no longer subject to the vagaries of competition. It was mandatory.

NARRATOR: Soon, seatbelts were required in every car. But getting people to use them was another matter.

SEATBELT PSA SONG: "Always buckle up. Put your mind at ease. Tell your riders, please. Get your seatbelts buckled. Everybody buckle up."

PENNY MARSHALL PSA: "You know, Edwin, if you loved me, you'd show me." (Edwin buckles his seatbelt.) "Oh, Edwin . . ."

"BELT SOMEONE" PSA SONG: "Belt your sister, la-ti-tah. Belt your brother, la-ti-tah. Belt your grandpa, belt your father . . ."

NARRATOR: But the ads didn't work. In 1970, fewer than 15% of all Americans wore seatbelts. The government called for a technological fix, a device that would restrain occupants in their seats, whether they liked it or not. The race was on to develop the airbag, then considered to be the ultimate passive restraint. It was a radical step; airbag deployments are violent events. They use explosives to generate the gas needed to fill the bag. And the bag itself deploys at 200 miles an hour. Creating safe airbags was an enormous challenge. And there were several false steps. Engineers had to determine how big the bag should be, what materials were best to use, and how to inflate them within 30 milliseconds after impact - without blowing them apart. When the airbag deploys, some gas does seep out. To be sure it wasn't toxic to humans, Mercedes carried out a series of tests. The first ones involved putting a cage full of canaries in the automobile.

INGO KALLINA: The canary has a wonderful feature. It's capable to trace for very small amounts of toxic gases. So, we used canaries in the interior of the passenger compartment, and they got nervous when they smell, or if they feet toxic gases, very small amounts.

NARRATOR: The canaries were unharmed by the gas, although they didn't like the noise airbags make when they deploy. In fact, humans were also tested to ensure that they could withstand the explosion without hearing loss. In 1980, Mercedes was the first to offer airbags as standard equipment. Eight years later, all cars sold in the United States were required to have airbags. And they are credited with saving thousands of lives. But a darker side to the airbag story would soon emerge.

ROBERT SANDERS: We were in a '95 Dodge Caravan that I had just purchased three weeks before. And my two sons, Matthew and David, were in the middle seat, and Alison was in the right front passenger seat. We were about a half mile from home when one of the boys in the back seat asked if we could have the Redskins football game on the radio. Alison immediately said, "I'll do it." And she threw the shoulder strap behind her and reached forward to find the game on the radio. I said to her, "Sit back and I'll find the game." When I looked up, I saw that the light at the next intersection had turned red. And I braked, but I couldn't prevent the car from entering the intersection and colliding into the side of a van that was stationary in the intersection, waiting to turn.

NARRATOR: The car's speed at impact was about nine miles per hour, and the damage was minimal. Both airbags deployed. The boys in the back seat were fine, but Alison was limp and unconscious.

ROBERT SANDERS: I screamed, "Alison!" I was just horrified. I couldn't understand how she could be in that condition.

NARRATOR: At the hospital, Rob learned that Alison had sustained a severe head injury and that she may be brain dead.

ROBERT SANDERS: I was completely out of my mind at that point. All I could do was scream over and over, "God save that precious child!" And I was so distraught and making so much commotion that passersby walking by the waiting room would look in, startled, because there was this man screaming.

NARRATOR: Alison died the next day. Shortly after, her family discovered she was the 12th child killed by an airbag in a low-speed collision. Injury can occur when the child's head is close to the airbag and struck in the first milliseconds of deployment. Several children have been decapitated this way. Another type of injury is called catapult.

ROBERT SANDERS: I don't know for a certainty which of the two injuries Alison sustained, but I believe it was the catapult type injury. The bag was under her chin, I believe, and at the moment of maximum fillage, the bag popped into full fillage and caused a tremendous, horrific blow on her head and neck. And I think it was aggravated, in fact, ironically, by the fact that she was wearing a lap belt. Her body was being held down while the airbag was pushing her head and neck upwards.

NARRATOR: With other grieving families, Rob formed a group to force the auto industry to post a prominent warning about the dangers of airbags in all new cars. The owners of older cars with passenger side bags received letters.

ROBERT SANDERS: The single most important thing that parents need to know is never, ever to seat a child in front of an airbag. Children must be seated in the back seat, properly buckled, preferably in the middle seat.

NARRATOR: By the end of 1998, 48 adults had also been killed by airbags, mostly small women.

JIM CHAMBERLIN: We try to tell people to stay at least 10 to 12 inches away from the steering wheel. If they have to get pedal extenders for their feet to reach the pedals, that's a possibility as well.

NARRATOR: On/off switches are also available in some cars. Although an airbag that is turned off won't kill anybody, it won't protect anyone, either. Rob Sanders is a strong proponent of airbags. But he is fighting hard for some basic changes in how they work.

ROBERT SANDERS: Some auto makers design them very well. For example, Mercedes, BMW, and Honda, in particular, have designed extremely good airbags that have killed no children whatsoever. Other auto makers, however, have designed very dangerous bags that have an overly aggressive force of deployment combined with a very low threshold. There is no reason to have an airbag go off in an eight-mile-an-hour fender-bender. The auto makers should simply raise the threshold to about 15 miles an hour. That one step alone would have saved the vast majority of the children who had been killed. The other thing they can do is put internal tethers inside of the airbag. It keeps it from extending too close to the child. Better designed systems have these internal tethers. Another thing is simply to have the seat track for the seat not allow the seat to get too close to the dashboard. This also isn't a very high-tech technology.

NARRATOR: But high technology may provide the ultimate solution: an airbag system with a brain that decides for itself when and how the bag should deploy, based on certain criteria. Under the seat is an electronic "scale" that directs the bag to deploy only if the rider is above a certain weight. On the dash is an ultrasound sensor to determine the size and location of the person in the seat. At the heart of the system, a computer.

JIM CHAMBERLIN: We need to know how severe the crash is, the size of the occupant, whether the occupant is too close to the airbag or all the way back, whether the buckle is engaged or not. And based on that information, we will have a soft airbag or a very fast, hard airbag, or no airbag at all.

NARRATOR: The bag itself looks the same as today's systems, but can deploy at two different speeds. This is the airbag module. It is designed with a single canister that holds the gas that fills the bag. On top, there are two initiators. In a minor accident, only one initiator fires, and the bag inflates smaller and softer. In a high-speed accident, both initiators fire, and the bag fills completely. The third option is no deployment at all. When an infant seat is placed in front of an airbag, the sensors recognize this dangerous situation and prevent the bag from opening. Smart airbags won't show up in cars for several years, leaving in place a system that is life-saving for many, but decidedly unsafe for some. After 100 years, cars are much safer than they have ever been. But there is one thing that hasn't changed, the most dangerous threat of all: the human behind the wheel. Each year, 40,000 Americans die in car accidents. Ninety percent are caused by human error. The solution might be to take the human out of the driver's seat entirely.

TERRY QUINLAN: Most everyone thinks they're a good driver, but we're human, we make mistakes. And those mistakes cause fatalities, injuries. A computer does not get sleepy. A computer does not get mad. A computer does not become distracted.

NARRATOR: And a computer can also drive a car. This platoon of automobiles is completely controlled by computers. The cars travel at 60 miles an hour, precisely 21 feet apart. For ten days, this was the highway of the future, the two middle lanes of a seven-mile stretch of road in San Diego, built by a group of universities, private industry, and government.

COMPUTER VOICE: Check in. Pass.

NARRATOR: A ride on the automated highway begins when the car takes over from the human.

COMPUTER VOICE: Speed control on. Steering control on.

NARRATOR: Foot off the pedal, hands off the wheel, and leave the driving to the computer.

TERRY QUINLAN: There are a number of different technologies that we're using to demonstrate the feasibility of automated highways. We're using little magnets embedded in the roadway to guide the vehicle down the center of the roadway.

NARRATOR: The magnets, in the center of the road, sense when a car is veering out of line and trigger the steering control to adjust. Then, magnets themselves are small, buried an inch under the road. They interact with three magnetometers attached under the front bumper. There is a radar screen on the front and back of each vehicle that maintains a safe distance between the cars. And obstacles on the road are no problem.

TERRY QUINLAN: We have very small cameras that actually look at the road and follow the lane stripes or oil slick, just as you or I would in looking at the road. There's a radar reflective stripe that looks similar to a paint stripe that we see on the road, magnetic stripes. There's a number of promising technologies that we can draw from to build an automated highway.

NARRATOR: What if something unexpected happens, like a breakdown? Here, the automated truck detects the car ahead with plenty of time to change lanes. But what would happen if the driver became ill?

CHUCK THORPE: When it comes to the off ramp at the end of the automated travel, and asks the driver if the driver is ready to take over. If the driver doesn't take over and do a competent job, the system will automatically pull the vehicle over to a safe spot, bring it to a halt, and send out a distress signal.

NARRATOR: But critics are skeptical that such a complex system can ever be truly reliable.

CHUCK THORPE: Elevators are reliable. A hundred years ago, people weren't sure that they trusted elevators until Mr. Otis had himself hauled up 45 feet in the air, and had the cable chopped and showed that his safety brake held. We have to do the same kind of things as we get ready to introduce this.

TERRY QUINLAN: I see the ultimate automated highway system as one that you can step out of your home, into your car, in your driveway, punch in your destination, and sit back from that point on. And of course, that is years off. But I have no doubt that that will happen.

NARRATOR: One of the goals of the automated highway system is to be collision-free. But 2,000 pounds of steel hurtling across the landscape at 60 miles an hour is inherently dangerous, and as long as we choose to drive, we may never completely escape the risk.

What do you need to know when accidents happen? Be prepared. Log on to NOVA's Web site, www.pbs.org.

The "Escape!" set is available on home video cassette for $49.95 plus shipping and handling. To order, call 1-800-949-8670.

NOVA is a production of WGBH Boston.

Major funding for NOVA is provided by the Park Foundation. Dedicated to education and quality television.

This program is funded in part by Northwestern Mutual Life, which has been protecting families and businesses for generations. Have you heard from the Quiet Company?

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And by the Corporation for Public Broadcasting and viewers and like you.

This is PBS.

ANNOUNCER: Ah, look! Turdus migratorius, or the common American Robin. Although invertebrates such as earthworms provide 40% of its diet, the Robin is chiefly a fruit-eating species, with the fledglings consuming an average of 100 meals a day. The adult will then remain at the nest throughout the night to guard against predators.

CHILD: Hey, Dad!

ANNOUNCER: Should danger threaten the family, it will become agitated and sound a call of . . . um . . .

CHILD: Hey, Dad!

BIRDWATCHING DAD: What, honey?

CHILD: Mom says come inside, because supper's ready!

BIRDWATCHING DAD: Oh. OK.

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ANNOUNCER: Heeding the fledgling's call, the male goes inside where he will eat pot roast.

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