Key Takeaway

Jury instruction was improper due to the highly technical evaluations in the design defect allegation


Soule v. General Motors Corporation

Soule v. General Motors Corporation

8 Cal.4th 548 (1994)


On the early afternoon of January 16, 1984, plaintiff was driving her 1982 Camaro in the southbound center lane of Bolsa Chica Road, an arterial street in Westminster. There was a slight drizzle, the roadway was damp, and apparently, plaintiff was not wearing her seat belt. A 1972 Datsun, approaching northbound, suddenly skidded into the path of plaintiff's car. The Datsun's left rear quarter struck plaintiff's Camaro in an area near the left front wheel. Estimates of the vehicles' combined closing speeds on impact vary from 30 to 70 miles per hour.

The collision bent the Camaro's frame adjacent to the wheel and tore loose the bracket that attached the wheel assembly (specifically, the lower control arm) to the frame. As a result, the wheel collapsed rearward and inward. The wheel hit the underside of the "toe pan"--the slanted floorboard area beneath the pedals--causing the toe pan to crumple, or "deform," upward into the passenger compartment.

Plaintiff received a fractured rib and relatively minor scalp and knee injuries. Her most severe injuries were fractures of both ankles, and the more serious of these was the compound compression fracture of her left ankle. This injury never healed properly. In order to relieve plaintiff's pain, an orthopedic surgeon fused the joint. As a permanent result, plaintiff cannot flex her left ankle. She walks with considerable difficulty, and her condition is expected to deteriorate.

After the accident, the Camaro was acquired by a salvage dealer, Noah Hipolito. Soon thereafter, plaintiff's son, Jeffrey Bishop, and her original attorney, Richard Hawkins, each inspected and photographed the car and its damaged floorboard area. The failed bracket assembly was retrieved. However, Hipolito later discarded the damaged toe pan, repaired the Camaro, and resold it. Thus, except for the bracket assembly, no part of the vehicle was retained as evidence.

Plaintiff sued GM for her ankle injuries, asserting a theory of strict tort liability for a defective product. She claimed the severe trauma to her ankles was not a natural consequence of the accident but occurred when the collapse of the Camaro's wheel caused the toe pan to crush violently upward against her feet. Plaintiff attributed the wheel collapse to a manufacturing defect, the substandard quality of the weld attaching the lower control arm bracket to the frame. She also claimed that the placement of the bracket, and the configuration of the frame, were defective designs because they did not limit the wheel's rearward travel in the event the bracket should fail.

The available physical and circumstantial evidence left room for debate about the exact angle and force of the impact and the extent to which the toe pan had actually deformed. The issues of defect and causation were addressed through numerous experts produced by both sides in such areas as biomechanics, metallurgy, orthopedics, design engineering, and crash-test simulation.

Plaintiff submitted the results of crash tests, and also asserted the similarity of another real-world collision involving a 1987 Camaro driven by Dana Carr. According to plaintiff's experts, these examples indicated that Camaro accidents of similar direction and force do not generally produce wheel bracket assembly failure, extensive toe pan deformation, or severe ankle injuries such as those plaintiff had experienced. These experts opined that without the deformation of the toe pan in plaintiff's car, her accident could not have produced enough force to fracture her ankles.

A metallurgist testifying on plaintiff's behalf examined the failed bracket from her car. He concluded that its weld was particularly weak because of excess "porosity" caused by improper welding techniques. Plaintiff's experts also emphasized the alternative frame and bracket design used by the Ford Mustang of comparable model years. They asserted that the Mustang's design, unlike the Camaro's, provided protection against unlimited rearward travel of the wheel should a bracket assembly give way.

GM's metallurgist disputed the claims of excessive weakness or porosity in the bracket weld. Expert witnesses for GM also countered the assertions of defective design. GM asserted that the Camaro's bracket was overdesigned to withstand forces in excess of all expected uses. According to expert testimony adduced by GM, the Mustang's alternative frame and bracket configuration did not fit the Camaro's overall design goals and was not distinctly safer for all collision stresses to which the vehicle might be subjected. Indeed, one witness noted, at least one more recent Ford product had adopted the Camaro's design.

A second major thrust of GM's defense was that the force of the collision, rather than any product defect, was the sole cause of plaintiff's ankle injuries. Using the results of accident reconstruction, computer simulations, and actual crash tests, GM sought to prove that the probable collision force concentrated on the left front wheel of plaintiff's Camaro exceeded the "yield strength" of any feasible weld or design.

By similar means, GM also sought to show that plaintiff's ankle injuries were not caused by the upward movement of the toe pan, but by the inertial forward and downward motion of plaintiff's unrestrained body and legs against the toe pan at the instant of impact. From plaintiff's other injuries, and from photographs showing the general pattern of damage to the Camaro's interior, GM's experts inferred that plaintiff was not wearing her seat belt and had locked or braced her legs in reaction to the imminent collision.

Hence, they concluded, her rigid ankles had absorbed the full force of her inertial forward movement, which was sufficient to cause the fractures. Based on their test results, GM's witnesses opined that plaintiff's ankles had probably moved forward, struck the toe pan, and broken before significant deformation of the toe pan occurred.

The court instructed the jury that a manufacturer is liable for "enhanced" injuries caused by a manufacturing or design defect in its product while the product is being used in a foreseeable way. Over GM's objection, the court gave the standard design defect instruction without modification. This instruction advised that a product is defective in design "if it fails to perform as safely as an ordinary consumer would expect when used in an intended or reasonably foreseeable manner or if there is a risk of danger inherent in the design which outweighs the benefit of the design."

The jury was also told that in order to establish liability for a design defect under the "ordinary consumer expectations" standard, plaintiff must show (1) the manufacturer's product failed to perform as safely as an ordinary consumer would expect, (2) the defect existed when the product left the manufacturer's possession, (3) the defect was a "legal cause" of plaintiff's "enhanced injury," and (4) the product was used in a reasonably foreseeable manner.

With respect to all theories of liability, the instructions indicated that " legal cause of injury is a cause which is a substantial factor in bringing about the injury." However, the trial court refused the following instruction proffered by GM: "If you find that the subject Camaro … was improperly designed, but you also find that would have received enhanced injuries even if the design had been proper, then you must find that the design was not a substantial factor in bringing about her injuries and therefore was not a contributing cause thereto."


We granted review to resolve three questions.

First, may a product's design be found defective on grounds that the product's performance fell below the safety expectations of the ordinary consumer if the question of how safely the product should have performed cannot be answered by the common experience of its users?

Second, in an action for enhanced collision injuries caused by an uncrashworthy vehicle, where a correct general instruction on legal cause is given, is it error to refuse a defense instruction that any defect cannot be a legal cause of injury if the accident would have produced the same injury even without the defect?

Third, if the refusal is error, is it reversible per se?


A manufacturer, distributor, or retailer is liable in tort if a defect in the manufacture or design of its product causes injury while the product is being used in a reasonably foreseeable way. Because traffic accidents are foreseeable, vehicle manufacturers must consider collision safety when they design and build their products. Thus, whatever the cause of an accident, a vehicle's producer is liable for specific collision injuries that would not have occurred but for a manufacturing or design defect in the vehicle.

In Barker v. Lull Engineering Co., (Barker), the operator of a high-lift loader sued its manufacturer for injuries he received when the loader toppled during a lift on sloping ground. The operator alleged various design defects which made the loader unsafe to use on a slope. In a pre-Cronin trial, the court instructed that the operator could recover only if a defect in the loader's design made the machine " 'unreasonably dangerous for its intended use.' " The operator appealed the defense verdict, citing the "unreasonably dangerous" instruction as prejudicial error.

The manufacturer responded that even if the "unreasonably dangerous" test was inappropriate for manufacturing defects, such as the substandard fastener material in Cronin, it should be retained for design defects. This rule would not produce the undue double burden that concerned us in Cronin, the manufacturer insisted, because unreasonable danger is part of the definition of design defect, not an additional element of strict product liability. Without this limitation, the manufacturer contended, juries would lack guidance when determining if a defect had sprung not from a mistake in supply or assembly, but from a flaw in the product's specifications.

The Barker court disagreed. It reasoned as follows: Our concerns in Cronin extended beyond double-burden problems. There we also sought to avoid the danger that a jury would deny recovery, as the Restatement had intended, "so long as the product did not fall below the ordinary consumer's expectations as to safety…." This danger was particularly acute in design defect cases, where a manufacturer might argue that because the item which caused injury was identical to others of the same product line, it must necessarily have satisfied ordinary consumer expectations.

Despite these difficulties, Barker explained, it is possible to define a design defect, and the expectations of the ordinary consumer are relevant to that issue. At a minimum, said Barker, a product is defective in design if it does fail to perform as safely as an ordinary consumer would expect. This principle, Barker asserted, acknowledges the relationship between strict tort liability for a defective product and the common law doctrine of warranty, which holds that a product's presence on the market includes an implied representation " 'that it safely do the jobs for which it was built.' " "Under this standard," Barker observed, "an injured plaintiff will frequently be able to demonstrate the defectiveness of the product by resort to circumstantial evidence, even when the accident itself precludes identification of the specific defect at fault."

However, Barker asserted, the Restatement had erred in proposing that a violation of ordinary consumer expectations was necessary for recovery on this ground. "As Professor Wade has pointed out, … the expectations of the ordinary consumer cannot be viewed as the exclusive yardstick for evaluating design defectiveness because 'n many situations … the consumer would not know what to expect, because he would have no idea how safe the product could be made.' "

Thus, Barker concluded, "a product may be found defective in design, even if it satisfies ordinary consumer expectations, if through hindsight the jury determines that the product's design embodies 'excessive preventable danger,' or, in other words, if the jury finds that the risk of danger inherent in the challenged design outweighs the benefits of such design." Barker held that under this latter standard, "a jury may consider, among other relevant factors, the gravity of the danger posed by the challenged design, the likelihood that such danger would occur, the mechanical feasibility of a safer alternative design, the financial cost of an improved design, and the adverse consequences to the product and to the consumer that would result from an alternative design.

Barker also made clear that when the ultimate issue of design defect calls for a careful assessment of feasibility, practicality, risk, and benefit, the case should not be resolved simply on the basis of ordinary consumer expectations. As Barker observed, "past design defect decisions demonstrate that, as a practical matter, in many instances, it is simply impossible to eliminate the balancing or weighing of competing considerations in determining whether a product is defectively designed or not…."

An example, Barker noted, was the "crashworthiness" issue presented in Self v. General Motors Corp. The debate there was whether the explosion of a vehicle's fuel tank in an accident was due to a defect in design. This, in turn, entailed concerns about whether placement of the tank in a position less vulnerable to rear end collisions, even if technically feasible, "would have created a greater risk of injury in other, more common situations." Because this complex weighing of risks, benefits, and practical alternatives is "implicit" in so many design-defect determinations, Barker concluded, "an instruction which appears to preclude such a weighing process under all circumstances may mislead the jury."

In some cases, "ordinary knowledge … as to … characteristics" may permit an inference that the product did not perform as safely as it should. If the facts permit such a conclusion, and if the failure resulted from the product's design, a finding of defect is warranted without any further proof. The manufacturer may not defend a claim that a product's design failed to perform as safely as its ordinary consumers would expect by presenting expert evidence of the design's relative risks and benefits.

However, as we noted in Barker, a complex product, even when it is being used as intended, may often cause injury in a way that does not engage its ordinary consumers' reasonable minimum assumptions about safe performance. For example, the ordinary consumer of an automobile simply has "no idea" how it should perform in all foreseeable situations, or how safe it should be made against all foreseeable hazards.

An injured person is not foreclosed from proving a defect in the product's design simply because he cannot show that the reasonable minimum safety expectations of its ordinary consumers were violated. Under Barker's alternative test, a product is still defective if its design embodies "excessive preventable danger," that is, unless "the benefits of the … design outweigh the risk of danger inherent in such design." But this determination involves technical issues of feasibility, cost, practicality, risk, and benefit which are "impossible" to avoid. In such cases, the jury must consider the manufacturer's evidence of competing design considerations, and the issue of design defect cannot fairly be resolved by standardless reference to the "expectations" of an "ordinary consumer."

As we have seen, the consumer expectations test is reserved for cases in which the everyday experience of the product's users permits a conclusion that the product's design violated minimum safety assumptions and is thus defective regardless of expert opinion about the merits of the design. It follows that where the minimum safety of a product is within the common knowledge of lay jurors, expert witnesses may not be used to demonstrate what an ordinary consumer would or should expect. Use of expert testimony for that purpose would invade the jury's function and would invite circumvention of the rule that the risks and benefits of a challenged design must be carefully balanced whenever the issue of design defect goes beyond the common experience of the product's users.

By the same token, the jury may not be left free to find a violation of ordinary consumer expectations whenever it chooses. Unless the facts actually permit an inference that the product's performance did not meet the minimum safety expectations of its ordinary users, the jury must engage in the balancing of risks and benefits required by the second prong of Barker.

Accordingly, as Barker indicated, instructions are misleading and incorrect if they allow a jury to avoid this risk-benefit analysis in a case where it is required. Instructions based on the ordinary consumer expectations prong of Barker are not appropriate where, as a matter of law, the evidence would not support a jury verdict on that theory. Whenever that is so, the jury must be instructed solely on the alternative risk-benefit theory of design defect announced in Barker.

The crucial question in each individual case is whether the circumstances of the product's failure permit an inference that the product's design performed below the legitimate, commonly accepted minimum safety assumptions of its ordinary consumers.

We fully understand the dangers of improper use of the consumer expectations test. However, we cannot accept GM's insinuation that ordinary consumers lack any legitimate expectations about the minimum safety of the products they use. In particular circumstances, a product's design may perform so unsafely that the defect is apparent to the common reason, experience, and understanding of its ordinary consumers. In such cases, a lay jury is competent to make that determination.

Applying our conclusions to the facts of this case, however, we agree that the instant jury should not have been instructed on ordinary consumer expectations. Plaintiff's theory of design defect was one of technical and mechanical detail. It sought to examine the precise behavior of several obscure components of her car under the complex circumstances of a particular accident. The collision's exact speed, angle, and point of impact were disputed. It seems settled, however, that plaintiff's Camaro received a substantial oblique blow near the left front wheel, and that the adjacent frame members and bracket assembly absorbed considerable inertial force.

An ordinary consumer of automobiles cannot reasonably expect that a car's frame, suspension, or interior will be designed to remain intact in any and all accidents. Nor would ordinary experience and understanding inform such a consumer how safely an automobile's design should perform under the esoteric circumstances of the collision at issue here. Indeed, both parties assumed that quite complicated design considerations were at issue and that expert testimony was necessary to illuminate these matters. Therefore, injection of ordinary consumer expectations into the design defect equation was improper.


The trial court erred by giving an "ordinary consumer expectations" instruction in this complex case. Moreover, the court should have granted GM's request for a special instruction explaining its correct theory of legal cause. However, neither error warrants reversal unless it caused actual prejudice, and both errors were harmless on this record.

The trial court erred when it instructed on the consumer expectations test for design defect, and when it refused GM's special instruction on causation. However, neither error caused actual prejudice.