Before Judges Baime, A.a. Rodr¡guez and Kimmelman.
The opinion of the court was delivered by: Baime, P.j.a.d.
 Argued November 18, 1998
On appeal from Superior Court of New Jersey, Law Division, Middlesex County.
Plaintiff suffered catastrophic injuries when the automobile in which she was a rear seat passenger struck a utility pole. After settling with the owner and driver of the automobile, plaintiff proceeded to trial against Nissan Motor Corporation and Nissan Motor Manufacturing Corporation, asserting design defect and failure to warn claims. More specifically, plaintiff contended that Nissan equipped the automobile with a defectively designed seat belt and failed to warn passengers of the potential for enhanced injuries if worn above the lower abdomen. Following a protracted trial, a jury found that the seat belt was defective but that the defect was not a proximate cause of plaintiff's injuries. The Law Division granted plaintiff's motion for a new trial as to all issues. Nissan sought leave to appeal, contending that the jury's verdict should be reinstated. Plaintiff filed a cross-motion for leave to appeal, arguing that the jury's finding of a product defect should be preserved, and that the new trial should concern only the question of proximate cause and damages. We granted both motions.
We need not recount the facts at length. On May 14, 1994, plaintiff, then twenty-three years old, and several friends spent the night in Hoboken attending a bar and a private party. Although the facts were disputed, it appears that plaintiff consumed substantial alcoholic beverages in the course of the evening.
At approximately 5:00 a.m. the next day, plaintiff and her two friends, Thomas Pezza and Stacy Sachais, left the party and entered Sachais's 1988 Nissan Sentra. Pezza sat in the driver's seat, Sachais in the front passenger seat and plaintiff in the rear passenger seat behind Sachais. Neither Pezza nor Sachais wore seat belts. Plaintiff wore the two point lap belt provided for the rear seat.
Obviously inebriated, Pezza drove the automobile approximately twelve blocks, swerving slowly from right to left. Ultimately, the vehicle swerved off the right side of the road, striking a utility pole. At the point of impact, the car was traveling at approximately twenty-two to twenty-eight miles per hour. When emergency crews arrived, they found Pezza unconscious and slumped over the steering wheel. Pezza suffered only minor injuries. When Sachais was removed from the automobile, she smelled of alcohol and appeared combative and disoriented. She, too, suffered only comparatively minor injuries.
Plaintiff was found seated in the rear passenger seat, wearing her lap belt and leaning against the right rear window. She was immediately transported to Jersey City Medical Center. Medical personnel noticed a deep bruise beginning on the area of plaintiff's naval and extending across her right side ending on her right flank. Dr. Paul Vessa, plaintiff's treating spinal surgeon, concluded that the bruise was the result of blunt trauma caused by plaintiff's violent contact with the lap belt. According to Vessa, plaintiff suffered a "hyperflexion distraction injury" caused by the lap belt holding her pelvis in the seat, which allowed for the "unrestrained forward flexion of her upper torso." Plaintiff's spinal column was "literally ripped in half," disabling all parts of her body below the naval. Moreover, the injury resulted in a loss of blood circulation to plaintiff's small and large intestines which ultimately became gangrenous. The problem was eventually resolved by way of a colostomy.
Much of the testimony at trial pertained to plaintiff's pre-impact seating position. The experts unanimously agreed that to minimize the possibility of injury, a rear seat occupant should wear a lap belt restraint low on the hips, with the belt positioned on the anterior-superior portion of the passenger's iliac crest. Plaintiff contended that she was in an upright position at the point of impact. Plaintiff's experts asserted that Nissan had installed the seat belt anchorages in an asymmetrical manner, causing the lap restraint to "ride up" too high on the occupant's abdomen, contrary to federal motor vehicle standards. They asserted that the lap belt was inherently dangerous and breached consumers' reasonable expectations of safety. They further claimed that Nissan failed to warn users of the dangerous qualities of the lap restraint as part of her design defect claim. Plaintiff contended that safe and reasonably feasible alternatives existed at the time the vehicle was manufactured, which would have obviated the dangers posed by the lap restraint installed by Nissan. Specifically, it was argued that a three point shoulder harness lap belt would have prevented plaintiff's injuries. It was also asserted that a safer two point lap belt, which would not rise above the passenger's hips, was a feasible alternative; however, plaintiff's evidence on this point was far less detailed and specific.
In contrast, Nissan's experts concluded that plaintiff was in a slumped position tilting to her left with the seat belt positioned over her naval when the accident occurred. Based upon the pattern of bruises and the nature of the injuries sustained, they asserted that plaintiff was reclined to the left with her torso at a forty-five to ninety degree angle. Nissan's experts testified that the two point lap belt system with which the automobile was equipped satisfied all federal, state and local safety standards. Significantly, they asserted that plaintiff would have suffered the same injuries had the vehicle been equipped with the shoulder harness lap restraint system recommended by plaintiff's experts. According to their testimony, the "shoulder belt" would have locked upon the forward movement of the body propelled by the force of the collision, and would have "strategically . . . followed the lie of the lap belt." They opined that the torso would have "follow[ed] a horizontal arc," tearing the spinal column and resulting in the same injuries.
The trial court submitted the case to the jury based upon the three theories urged by the plaintiff. In describing plaintiff's design defect claim, the trial court told the jury to employ a "risk-utility analysis" to determine whether the danger posed by the product outweighed its benefits. Among the factors to be considered was "the availability of a substitute product or products, at the time the particular vehicle in question was manufactured, or sold, . . . which would meet the same needs or perform the same function as the product [in question], but without containing the alleged defect. . . . In other words, . . . a more safely designed product." The court stressed that Nissan's responsibility in designing the seat belt system included the duty to prevent an injury caused by the foreseeable misuse of the product. The jury was told that in applying its risk-utility analysis, it was to consider whether a reasonably feasible alternative design existed at the time the automobile was manufactured that would have cured the defect which allegedly caused plaintiff's injuries. Because this portion of the trial court's instruction is critical to our analysis of the issues presented, we quote the pertinent part of the Judge's charge:
Plaintiff must also prove . . . that there was available an alternative safer design, practicable under the circumstances, which would have eliminated the alleged defect in the internal restraint system and [would have] prevent[ed] her from being injured to the extent she was. Plaintiff must prove to what extent the defect in the vehicle enhanced or increased the injuries she would have suffered had an alternative design been utilized.
The trial court charged the jury that plaintiff was also required to prove that the design defect proximately caused her injuries. The court defined proximate cause in its traditional sense as meaning that the alleged design defect must have constituted "a substantial factor in producing [plaintiff's] injuries." The court noted that "proximate cause means that the defect in the product was a substantial factor, which singly or in combination with another cause, created plaintiff's injuries." The court added, albeit in another part of its charge, that if the jury were to conclude that "plaintiff would have been injured . . . as she was, even if the vehicle had ...