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David Gordon Wilson


Much publicity is given to "horror stories" of seemingly excessive judgments against apparently ethical manufacturers after they have been sued by unscrupulous people pretending to be victims of what is claimed to be deficient design. However, these reports are far from representative of the actual situation. It is pointed out in this paper that the other side of this story is that product-liability litigation is decreasing quite markedly in the US; that this form of litigation brings about major improvements in product design and in the safety of the public; and that it is possible to avoid most negative impacts of such litigation by striving for, and documenting. excellence in the design and manufacturing of products, by clearly warning users of dangerous situations, and by putting trust in insurance that is standard for the industry.



In many areas of modern life we are driven by what we know of extreme cases: only these are reported by news organizations. Here is a recent .example (disguised so that your author does not get sued! I was an "expert witness" for one of the manufacturers involved).

"Bill", a young American, bought a regular "road" bicycle for recreation. He found that he liked biking, and hearing that sew-up tires are used by racing cyclists and would enable him to go faster, bought new wheels and tubular tires and had them installed on his bike. One day he went with a group of friends on a ride that included the summit of a small mountain. While pausing at the top he joked to his friends that he had bad brakes, showing that with the brake levers fully squeezed against the handlebars he could move his bike easily back and forth. He then said "Last man down the mountain buys the beers!" and rushed off down the steep, rough, bumpy, asphalt road with the others in hot pursuit. The road had signs showing a speed limit of 35 km/h.and,after about a kilometre, a warning of a sharp S-bend. The person who was closest behind Bill said that as he approached the bend his cycle-computer was registering about 75 km/h and that Bill was out of sight ahead of him. He braked to get around the bend and saw that Bill had hit a stone wall and was lying on his back some distance from his bicycle.

Bill had severed his spinal cord and was, tragically, a quadriplegic from then on. He gave his bike to a family member, who, after having the front wheel and fork replaced, used it regularly. Bill confessed at some point that the accident was his fault. However, after over a year he (or possibly his insurance company) decided to try to get some money through the courts, and his lawyer sued the bicycle shop that sold him the bike, the bicycle manufacturers, and the supposed manufacturers of the rims and the tires (the actual wheel and tire had been disposed of). One would have thought that these companies would have had a very strong case. Yet one by one they, or rather their insurance companies, all "settled out of court", meaning that they agreed to pay large sums to the plaintiff to avoid the far-larger costs of going to trial. They also may have felt that, however strong their case, the sight of this young man sitting paralyzed in a wheelchair. with his wife and child, would be enough to make an American jury decide that these insurance companies were rich and Bill and his family had already been punished terribly. To award him a large settlement even though he was at fault could be possibly some form of jury-administered social justice.

The present status of product-liability litigation in the US.

Cases like this seem to be typically American. In what is considered to be a free-enterprise system (but is in fact increasingly regulated) the absence of a socialist health-care and welfare system seems to give credence to reports of juries leaning to the "left". They are drawn largely from the lower end of the economic spectrum because professional people try to find reasons to be excused from jury service. However, contrary to popular belief, jurors do not overwhelmingly sympathize with individual plaintiffs at the expense of companies. According to Jury Verdict Research reported in Business Week on November 8, 1993, defendants won 57 percent of the products-liability suits in 1992. Popular opinion also paints a picture of a flood of products-liability litigation. In fact, products-liability lawsuits were less than 1 percent of the total state and federal caseload in 1994[1]. (There is a huge backlog of lawsuits awaiting trial in most US jurisdictions, but most cases are suits between businesses and suits between family members, particularly divorce cases). The number of product-liability lawsuits is also in sharp decline, having dropped 40 percent between 1985 and 1991. Insurance premiums covering product liability dropped 45 percent between 1987 and 1993[2].

There is also concern regarding so-called "punitive damages" awarded by some courts. These are imposed for particularly egregious cases in some states (punitive damages are not allowed in many states. including Massachusetts) and are derived from ancient Roman and English law[3]. In fact, apart from the special and shocking case of asbestos liability, the awarding of punitive damages is very rare in the US, under ten cases per year. A velomobile/HPV manufacturer would have to be very delinquent, or exceedingly unlucky, to be included in this number.

The remaining fear of liability lawsuits.

So far I have given some details of the type of case that strikes fear in the heart of small manufacturers who are concerned that one such lawsuit could put them out of business; and I have also tried to show that much of the concern is exaggerated. However, I should describe how lawsuits come about and are adjudicated or settled in order to give manufacturers of velomobiles, particularly those outside the US, an understanding of the risks and rewards of exporting to the United States.

The US is a country where even a poor person can sue the world's largest corporation. To do so she/he needs to persuade a lawyer who specializes in this type of case that her/his injuries or other harms are sufficiently serious to justify taking action. The lawyer will generally do this on a "contingent-fee" basis: that is, she/he will charge the client nothing for his/her services, but will take 25 - 33% of any monetary award. This has the socially desirable consequence that people of limited wealth are given full access to the courts in cases where they have been harmed. Although occasional large awards receive a great deal of publicity, juries are generally hard-headed and reasonable in awarding damages.

Most cases, however, do not go to trial. The early stages of a lawsuit are taken with "discovery", a process in which each side is required to make available all relevant written records and all relevant people to give depositions. So-called expert witnesses are hired by both sides to add weight to the testimony. The discovery process can be a time-consuming, disruptive and costly time for a manufacturer, although the attorneys' and experts' costs are usually handled by the insurance company. The opposing lawyers can demand, however, all drawings, sketches, notes and other records that have any possible connection with the injury to the plaintiff. Each item considered actually relevant is labelled as "Exhibit A, B" etc. During this period the attorneys for each side are assessing their situations and their likelihood of winning or losing in the trial. At some point the lead attorney on one side will contact the lead attorney on the other side and say something like the following. "As a result of discovery and depositions we have an overwhelming case, and your side is likely to have to pay large sums if we go to trial. My client has expressed a willingness to settle out of court for a payment of X dollars." Sometimes the other attorney accepts the offer with alacrity. More often there is a period of negotiation, as in a market anywhere. In under ten percent of cases agreement is not reached, and a trial date is set. This may be several years after the suit is filed.

I believe that this procedure is fair and leads to social justice in the large majority of cases. It is difficult to be fair in cases where a life has been lost or serious permanent injury has resulted from a product defect. Suppose, for instance, a promising young person just married and just launched on a promising career is permanently confined to a wheelchair because the fork of a new bicycle snapped in normal use. No amount of money could compensate this person and her/his spouse and family for the terrible change in the quality of their lives for perhaps the next fifty years. The medical-care costs alone could amount to a huge sum. Such cases could be regarded as the norm in malpractice lawsuits against the medical profession, which takes extraordinary steps to prove that every decision and procedure taken has been for the best. A whole battery of very expensive tests will often be specified for a minor ailment, purely to ward off a suit against supposed malpractice in the event that a patient's recovery is not all that might be expected. The manufacturer of a human-powered vehicle does not need to go to these extremes. However, she/he must likewise take very conscientiously, and document in some way, the design and manufacture of any component the failure of which could cause, with reasonable probability, serious injury or death.

Manufacturers in countries where liability litigation is rare might well react with some alarm at having to take major precautions to avoid being sued, and to face unwelcome prying into their design, manufacturing and business practices if they are sued. These seem to be the price we pay to have markedly safer products in the US (and increasingly the safety advances achieved in the US partly through liability lawsuits have been adopted in Europe and elsewhere). Consider the alternatives.

It is claimed above that the quality of design and manufacture is enhanced by the possibility of liability litigation. There is, however, some question about the benefits that occur if a case is settled out of court, because of the secrecy that is more marked in the US than in, at least, Britain. (My professional field is turbine design, and the catastrophic failure of a turbine in Britain is followed by a full exposure of the causes, and the steps taken to cure the problem, in papers presented to the Institution of Mechanical Engineers. This public airing seldom occurs in the US, except in the case of airline crashes.) However, I believe that the message does get broadcast. An example is a case in which I served as an expert witness. A linesman working on overhead wires while on a truck-mounted aerial ladder was severely injured when the ladder suddenly collapsed, dropping him to the pavement. The cause was relevant to safety in HPVs: the ladder was operated by wire ropes that passed around several sheaves (figure 1). The sheave diameter was only seven times the wire diameter. The standards set by the wire-rope manufacturers are that the sheave/rope diameter ratio should be 72 for long life, with 42 being an absolute minimum. At a ratio of 7, the rope was bound to have a very short life before metal fatigue caused it to fail without warning. (The parallel with HPVs is that bicycle brakes and gear-shift cables are taken around pulleys and bends with a diameter ratio of far less than 42, and also fail periodically without, usually, any warning.)

Figure 1. Sheave/rope diameter ratios

From a guide by Armco Steel

sheaves.gif (5364 bytes)

When the lawyers for the two sides agreed on an out-of-court settlement, I became very disturbed that workers would be killed or injured because now, it seemed, the information about the extreme hazard that these ladders and booms posed would not be made public. The attorneys agreed with me that my professional engineering ethics outweighed my expert-witness responsibilities, and allowed me to try to send warnings of the extreme danger of these ladders to unions and other places. However, I believe that the manufacturer recalled the trucks faster than did any actions resulting from my warnings: the company did not want to face the rash of lawsuits that it now knew would be certain to come. Liability litigation had worked! Why doesn't it work to give us safe brake cables? I have had many cables, and handlebars, and cranks break, but fortuitously never at a critical time. If I had, there would have been a strong probability of a fatal accident, and, because bicycle accidents are usually not investigated with any degree of seriousness, the cause would not have become known.

Would it be better without lawyers willing to sue?

Contrast the recent US situation with that in Britain when I last lived there, in the 1960s. As an example, on one occasion I went to the National Health doctor specified for my district after I had had a sore throat for several weeks. With very few questions he told me to lower my pants, and jabbed a needle into my right buttock. By the next day the sore throat had cleared up magically. But my right leg grew huge and red and hot and very itchy. I could sleep at night only by lying in a tub of cold water. I went back to the doctor twice during the next two weeks as the swelling spread over the rest of my body, increasing my weight 17 kg. He waved me airily away. "It will go down!" he said. At about that time I had to fly to Boston to be introduced to the firm that had just hired me. My new boss met me at the airport: I was trying to disguise my sorry condition. From a distance of 20 m he cried out "What's the matter with you, Dave? You look as if you have a penicillin allergy!" He rushed me to his doctor, who said that I could have been dead in another 24 hours because the swelling was closing off my airways, and he treated me expertly so that I was fully recovered within five days.

There are several other similar anecdotes that I could tell about medical care in Britain, at least one occurring to a friend relatively recently. To me, there is one principal conclusion: physicians there have, or had, absolutely no concern about being sued. In the apparent absence of any other form of control they had absolute power. And absolute power corrupts. I have no doubt that many cases of malpractice were quietly swept under the rug. That leads inevitably to another rather startling conclusion. Britain has too few lawyers pursuing malpractice cases. They may not take cases on a contingent-fee basis, and they are also liable to face payment of costs if they lose a case. I am sure that this is also true of many other countries. Another conclusion is that the perceived (not necessarily the real) costs of medical care will undoubtedly seem lower in Britain than in the US.

If I had to choose between just these two alternatives, I would unhesitatingly take the US system, even though it makes engineering design and production a little more expensive. It produces a far safer society. If this were a paper about the reform of liability and malpractice law I could quote several authors who have proposed improvements that should bring about a happy compromise between these two alternatives (Linowitz[4], Bok[5]). But this paper is about the impact of the existing US system on the design of advanced human-powered vehicles. This is the topic of the next section.


The perceived impact of liability laws in the late 1970s on the design of the Avatar 2000, which we believed to be the first recumbent bicycle to be produced for general sale since the 1930s, was the following. The initial impetus for the design was my concern for safety[6], because I had seen many reports of riders of regular "road" bicycles being severely injured or killed after going head-first over the handlebars on applying the front brakes too hard, or riding into a grating or hole in the pavement, or having baggage or a stick get caught in the front wheel, for examples. It seemed to me to be safer to go feet first. It was easy to list, in addition. other virtues that would improve safety: the near-impossibility of catching one's pedals on the road; the great improvement in the ability of the rider to see forward and to the side; the improved braking capability on both wheels; the shorter reaction time resulting from the hands being on or close to the brake levers at all times; and the lessening of injuries because riders are closer to the ground than when on road bikes. There were, and are, a few negative aspects to recumbents: the view to the rear is more circumscribed unless one uses a rearview mirror: and it is difficult to recover from a skid because of the low centre of gravity and the attendant rapidity with which one is "dumped" on the ground. The "safety balance" is clearly in favour of the recumbent. However, we knew that we would not receive large cheques from grateful riders who felt that our bicycles had saved them from serious injury. We would be more likely to be sued for larger amounts in those few areas in which our design might be worse than that of upright bicycles. (Designers of three- and four-wheeled vehicles have other advantages and disadvantages, of course).

We responded to this dilemma was in three ways:

1. we made the bicycle as safe as practicable;

2. we gave prolific warnings about possibilities of danger: and

3. we took out an insurance policy that was standard for (small?) bicycle manufacturers.

Figure 2. The Avatar 2000

avatar.jpg (59794 bytes)

We discussed the positive and negative features of the bicycle design with the insurance representative, who felt comfortable in giving Fomac, manufacturers of the Avatar, a policy that would apply to manufacturers of regular bicycles. There was an indication that if the Avatar turned out to be as much of an improvement in safety as we claimed, our rates might even be reduced. This gave an added incentive, if one was needed, to increase safety in our design wherever possible. As mentioned above, insurance rates for liability have in fact dropped markedly since that time.


Insurers are therefore major players in liability litigation, frequently almost taking the place of the defendants in pretrial organization of the defense and in the trial itself. Their role is that of insuring against risks to businesses, and of doing it in a way that is least costly to manufacturers (otherwise they would go to other insurers) while making a profit themselves. Insurers have a major stake in litigation, and have an obligation to ensure that any settlement is not greater than the limits of the insurance that has been purchased by the manufacturer. An insurer (meaning an individual agent or the firm she or he represents) may decide to settle out of court even though many may believe the case to be defensible, as in the example quoted above, simply to avoid the continuing high costs of attorneys and expert witnesses and the large amount of time that its own personnel will be spending on defending the suit.

An insurer might also be behind Bill's late decision to bring suit. If he had a policy that covered the medical consequences of accidents, his insurance company could well have contemplated the enormous lifetime costs of providing medical and other services and have taken the decision to institute the suits. Sometimes American courts play out dramas in which one family member may bring suit against other family members, a seemingly highly distasteful procedure. The suit may, however, be required by provisions in small print in the insurance policies, not by any previous ill-will in the family. There is, therefore, economic justification for this type of suit. It would be better if a system could be devised that was not so wasteful and invidious for the parties involved: a large proportion of any funds transferred from the defendants to the plaintiffs goes to legal costs, and the proceedings are likely to split families apart.


Design education has been helped by liability litigation. At M.I.T., and I'm sure at most universities, concern about the impact of litigation on engineering has led to an much-increased emphasis on engineering ethics and our responsibilities to society. The disaster to the Challenger space shuttle was a shock that brought about changes, particularly after it was found that engineers who had been fighting to have the launch put off because of what seemed to them obvious flaws in the low-temperature performance of some seals had been overruled by policy-makers, some of whom were also engineers. Our students are shown a videotape of a talk by one of the "whistle-blowing" engineers involved in the Challenger case, and many are moved to tears. We examine other case studies for lessons to be learned. For instance, one of the first skyscraper fires occurred in a New York building on the 37th floor, far too high to be reached by ladders. The first group of firemen decided to take the elevator to the 38th floor, break through the ceiling and spray water on the fire. However, the elevator stopped on the 37th floor, the doors opened automatically, and all were killed. The elevator was one of the first to be operated by heat-sensitive buttons, and these naturally stopped it where the fire was blazing. We ask our students how it was that in the several years required to invent, develop and manufacture this elevator-control system, no one in the company making them, nor in the architectural engineering offices specifying the use of the buttons, ever considered what would happen in the case of a fire. It seems likely that one or more people did think of this possibility, but were overruled. One obvious conclusion is that, like the British physicians mentioned above, no one was concerned about being sued for malpractice. Yet it is surely malpractice to design and install a device that, although it works wonderfully for every expected use, will kill or injure in an unexpected, but not unlikely. situation.

Can concern for safety go too far?

Designs analogous to heat-sensitive buttons for elevators can be found in many areas. Only a few years ago we drove cars that had rigid steering columns ready to pierce drivers' chests even in a low-speed collision. Now we have cars in which the driver and occupants are surrounded by air bags and restrained by belts and protected by a passenger compartment that will allow people to walk away from a frontal collision at 60 km/h and higher. Some research has found that some drivers like to operate their vehicles at an exciting level, a level at which they perceive a certain degree of danger. Give them seat belts and airbags and their average speed increases so that they feel the same degree of safety or danger. On the other hand, there is in the US at present an enthusiasm for huge sports-utility vehicles, partly because they are much more likely to survive, along with their drivers and passengers, in collisions with regular automobiles. The safety of others, including pedestrians and riders of HPVs, has thereby decreased. There is, therefore, an optimum level of safety engineering. This level should be found by estimating the benefit-cost ratio of any proposed change, evaluated over the whole affected population, not just the users of the new system[7]. The "benefit" side of such analyses requires the invidious decision on what value to put on human lives saved. Perhaps it is justifiable to avoid this thorny question by using, instead, the expenditures that could be predicted as having been avoided in litigation lawsuits. In either case, benefit-cost analyses would indicate that some proposed safety measures had gone too far. It is also certain that safety aspects of bicycles, regular and recumbent, would be found to have not received enough attention. We cheerfully ride bicycles with brakes that wear fast and don't stop us safely, on rims and tires that can explode at at least a thousand times the frequency of those on motor vehicles, and so forth. There are several ways (research and development, industry standards and government regulation being three) whereby improvements in our HPVs can be attained. We may have to depend on a fourth way: liability litigation.


The threat of US liability litigation has been exaggerated, especially with regard to human-powered vehicles. The many US manufacturers of recumbent bicycles and other velomobiles are not being overtaken by a flood of lawsuits. The quality of design and manufacture of the great majority of vehicles is very high, some of this high quality undoubtedly having been brought about by the desire of the designers and manufacturers to be able to stand up in court to defend their work. Liability-insurance rates for manufacturers have actually fallen as a result of the increased safety brought about by lawsuits and by regulation, and the insurance companies take most of the impact should a suit be filed. Finally, if a suit is filed and goes to trial, the great majority of US juries make fair and reasonable awards.


Attorneys Neil Sugarman and Phillip M. Davis were kind enough to read early drafts of this paper and to give valuable advice and documents that I have incorporated in the final version. My spouse Ellen Wilson also gave much-appreciated criticism. I am most grateful for their help.

David Gordon Wilson

M.I.T. room 3-455
77 Massachusetts Avenue
Phone: 617 253 5121
FAX: 617 258 0185


[1] Anon (1996). "Facts about the American civil justice system". American Bar Association publication, reviewed in the magazine Trial, November 1996. pp. 89-91.

[2] Anon (1995). "Product-liability insurance experience, 1984-1993". Consumer Federation of America, March, reported in a leaflet "Myths and facts about product-liability lawsuits".

[3] Rustad, Michael and Thomas Koenig (1993). "The historical continuity of punitive damages awards: reforming the tort reformers". The American Law Review, vol. 42 no. 4.

[4] Linowitz, Sol M. (1994). The Betrayed Profession. Charles Scribner & Sons, NY.

[5] Bok, Derek (1993). The Cost of Talent. The Free Press (Macmillan), NY.

[6] Wilson, David Gordon, Richard Forrestall, and Derek Henden (1984). "Evolution of recumbent bicycles and the design of the Avatar Bluebell." SAE paper 840021, Warrendale, PA.

[7] Wilson, David Gordon, and Joan G. Moore (1971). "Transportation resource allocation based on new methods of accident reporting." Accident Analysis and Prevention, vol. 3 pp. 121-138, Pergamon Press, NY.

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