Maywald v. Toyota: Arizona Reaffirms Two Independent Elements in Strict Products Liability and Narrows Risk/Benefit Analysis to the Challenged Design

1) Introduction

Parties. Plaintiffs/Appellants Shawn Maywald and Tanya L. Maywald sued Toyota Motor Corporation, Toyota Motor North America, Inc., and Overtyme, Inc. (collectively, “Toyota”).

Background facts. In December 2019, a northbound driver of a 2019 Toyota 4Runner fell asleep, crossed the center line, and collided head-on with the Maywalds’ southbound vehicle on State Route 77. Shawn Maywald suffered major injuries.

Claims and theory. The Maywalds asserted strict liability for design defect, negligent design, and loss of consortium, alleging the 4Runner was “defective and unreasonably dangerous” because it lacked lane departure warning (“LDW”) technology, which Toyota did not offer as standard or optional equipment.

Key issues before the Arizona Supreme Court. (1) Whether Arizona strict product liability requires a plaintiff to prove “defective” and “unreasonably dangerous” as independent elements; and (2) how to properly apply the consumer expectation test and the risk/benefit analysis, including whether risk/benefit compares the actual design to an alternative design.

2) Summary of the Opinion

The Court vacated the court of appeals’ memorandum decision and affirmed summary judgment for Toyota. It held that Arizona strict products liability requires proof of three distinct elements: (1) defect, (2) the defect rendered the product unreasonably dangerous, and (3) proximate cause. The Court clarified that the consumer expectation test and the risk/benefit analysis address only the unreasonably dangerous inquiry and do not eliminate the threshold requirement to show a defect.

Applying those principles, the Court concluded the 4Runner was not defective merely because it lacked LDW: the absence of a driver-assistance feature did not render the vehicle unsafe for normal handling and use, particularly where the accident resulted from a driver falling asleep. Because the Maywalds failed to establish defect, their strict liability claim failed at the threshold, and their negligent design and loss of consortium claims failed as well.

The Court also corrected the lower court’s approach to risk/benefit: it must focus on the risks and benefits inherent in the challenged design as sold (here, the 4Runner without LDW), not a head-to-head comparison between omitting LDW and including LDW as an alternative design.

3) Analysis

A. Precedents Cited

1. Foundational adoption of § 402A and Arizona’s two-part requirement

  • O. S. Stapley Co. v. Miller, 103 Ariz. 556 (1968): Arizona adopted strict product liability as stated in Restatement (Second) of Torts § 402A—liability for a product sold “in a defective condition unreasonably dangerous.” Maywald treats this language as establishing two distinct concepts.
  • Byrns v. Riddell, Inc., 113 Ariz. 264 (1976): Reaffirmed that a strict liability plaintiff must prove both that the product was defective and that the defect rendered it unreasonably dangerous. Maywald relies on Byrns as a central corrective to later “collapsed-element” formulations.
  • Rogers v. Unimac Co., 115 Ariz. 304 (1977): Clarified a plaintiff must prove the product was defective when it left the factory, the defect made it unreasonably dangerous, and the defect was the proximate cause of injury. Maywald uses Rogers both for the elements framework and to reject “could have used a different safety device” as sufficient, standing alone, to prove a design defect.

2. The “unreasonable danger” element as a limiting principle (strict vs. absolute liability)

  • Dart v. Wiebe Mfg., Inc., 147 Ariz. 242 (1985): Recognized consumer expectation and risk/benefit approaches, but included language suggesting “defective and unreasonably dangerous” could be resolved together. Maywald expressly disapproves any language in Dart that blurs the line between defect and unreasonable danger, while retaining Dart’s identification of the two tests for the unreasonable-danger inquiry.
  • Vineyard v. Empire Mach. Co., 119 Ariz. 502 (App. 1978): Cited to underscore that strict liability is not absolute liability.
  • Estabrook v. J. C. Penney Co., 105 Ariz. 302 (1970): Demonstrates the gatekeeping role of “defect”—no strict liability instruction is warranted absent evidence of defect, even where an injury occurs.

3. Re-centering the tests on “unreasonably dangerous” and defining “defect”

  • Readenour v. Marion Power Shovel, 149 Ariz. 442 (1986): Key authority for Maywald’s definitional framework: a product is defective when “unsafe for normal handling and consumption” (Restatement § 402A cmt. h), and strict liability attaches only where the defect makes the product “unreasonably dangerous.” Readenour also confirms consumer expectation and risk/benefit are used to determine unreasonable danger.
  • Bailey v. Montgomery Ward & Co., 6 Ariz. App. 213 (1967): Supports defining a defective article as not reasonably fit for ordinary purposes.
  • Jimenez v. Sears, Roebuck & Co., 183 Ariz. 399 (1995): Cited as the modern statement of strict liability elements; Maywald reaffirms and clarifies the interrelationship among those elements.

4. Disapproved “collapsed” formulations in intermediate appellate decisions

  • Dillon v. Zeneca Corp., 202 Ariz. 167 (App. 2002): Treated “defective condition unreasonably dangerous” as a singular showing and, according to Maywald, misread Gosewisch v. American Honda Motor Co., 153 Ariz. 400 (1987), which actually required the product be “in a defective condition and unreasonably dangerous.” Maywald disapproves Dillon to the extent it collapses the elements.
  • Golonka v. General Motors Corp., 204 Ariz. 575 (App. 2003): Treated satisfying either consumer expectations or risk/benefit as establishing both defect and unreasonable danger. Maywald disapproves that approach as eliminating the required distinction.
  • Gomulka v. Yavapai Machine & Auto Parts, Inc., 155 Ariz. 239 (App. 1987): Defined a design defect as a product made as intended but “unreasonably dangerous,” overlooking the independent defect requirement. Maywald disapproves the decision to the extent it conflates the elements.

5. Authorities on driver-assistance technology and the defect inquiry

  • Berkoski v. Honda Motor Co., 328 A.3d 986 (N.J. Super. Ct. App. Div. 2025): Persuasive authority holding that the absence of an available LDW system did not render an otherwise safe vehicle defectively designed, because the driver remains responsible for steering and lane keeping. Maywald adopts this reasoning.
  • Ortiz v. Daimler Truck North America LLC, 112 Cal. App. 5th 608 (2025): Distinguished as addressing duty/proximate-cause questions and expressly not deciding defect; therefore not informative on the threshold issue Maywald resolves (whether the product is defective in the first instance).

6. Other doctrinal anchors

  • Brown v. Sears, Roebuck & Co., 136 Ariz. 556 (App. 1983): Alternate safety features’ availability does not by itself establish defect.
  • Mather v. Caterpillar Tractor Corp., 23 Ariz. App. 409 (1975): Negligent design arises from failure to use reasonable care to make the product safe for intended uses; Maywald uses it to link negligent design to an underlying defect concept.
  • Barnes v. Outlaw, 192 Ariz. 283 (1998): Loss of consortium is derivative and requires a viable underlying tort claim.
  • Rosenberg v. Sanders, 256 Ariz. 359 (2023): Supplies the de novo summary judgment standard of review.
  • Barker v. Lull Eng'g Co., 573 P.2d 443 (Cal. 1978): Quoted (via Dart) for formulations of consumer expectations and risk/benefit balancing, but Maywald carefully limits how Arizona uses that framework.

B. Legal Reasoning

1. The Court’s clarified, ordered framework

Maywald crystallizes a procedural and analytic sequence:

  1. Defect first: the plaintiff must show the product was “unsafe for normal handling and consumption” (Readenour; Restatement § 402A cmt. h)—i.e., not reasonably fit for ordinary purposes (Bailey). If there is no defect, the strict liability analysis ends.
  2. Unreasonably dangerous second: only after defect is shown does the plaintiff prove the defect rendered the product “more dangerous than a consumer would expect or whose risks outweigh its benefits” (Readenour), using consumer expectations where feasible, otherwise risk/benefit (Dart, as constrained by Maywald).
  3. Proximate cause third: the plaintiff must show the defect caused the injury (Rogers; Jimenez).

This structure is the opinion’s central doctrinal move: it rejects years of drift in which consumer expectations or risk/benefit were sometimes treated as proving “defectiveness” itself. In Maywald’s view, that drift risked collapsing strict liability into something close to absolute liability whenever an injury occurred and a safer feature existed.

2. Why the 4Runner was not defective

The alleged “defect” was the lack of LDW (and functionally similar lane-departure prevention technologies). The Court held this omission did not make the vehicle unsafe for ordinary use because:

  • Ordinary consumers expect vehicles to be designed so that an attentive driver can drive within marked lanes; the Maywalds did not show the 4Runner failed that baseline expectation.
  • LDW may enhance safety but does not shift the “fundamental responsibility” from driver to vehicle; the law and common understanding require drivers to remain in-lane and awake (citing A.R.S. § 28-729(1)).
  • The accident scenario—falling asleep at the wheel—was treated as outside “normal use,” reinforcing why the absence of LDW did not render the vehicle unsafe for ordinary operation.
  • Consistent with Rogers v. Unimac Co. and Brown v. Sears, Roebuck & Co., the fact that a different or additional safety feature is feasible is not, by itself, proof of defect.

This reasoning effectively draws a line between (a) products that are unsafe in ordinary use because of a design characteristic and (b) products that could be made safer with additional technology but remain reasonably safe when used as intended.

3. Negligent design and loss of consortium fall with the absence of defect

Although strict liability and negligence focus on different questions (product condition vs. manufacturer’s reasonableness, per Dart), Maywald holds both design-based theories require a threshold showing that the product is defective for its intended uses (citing Mather). With no defect, negligence fails; and without an underlying tort, loss of consortium fails as derivative (Barnes).

4. The risk/benefit analysis must center on the challenged design (not an alternative-design face-off)

Even though the Court did not need to reach “unreasonably dangerous” once it found no defect, it corrected a recurrent analytical error: risk/benefit asks whether “the benefits of the challenged design . . . outweigh the risk of danger inherent in [the] design” (Dart). The court of appeals erred by comparing the risks of omitting LDW against the benefits of including LDW, which effectively treats an alternative design as the reference point.

Maywald permits consideration of alternatives only as inputs within the Dart/Byrns factors—especially “the availability of other and safer products” and “the ability to eliminate the danger without seriously impairing usefulness or making it unduly expensive”— but rejects an approach that would make manufacturers liable whenever a plausible additional safety feature exists.

C. Impact

  • Doctrinal cleanup and statewide uniformity. Maywald expressly disapproves portions of Dillon v. Zeneca Corp., Golonka v. General Motors Corp., and Gomulka v. Yavapai Machine & Auto Parts, Inc., and disapproves any blurring language in Dart v. Wiebe Mfg., Inc.. Trial courts now have a clearer, ordered checklist: defect → unreasonably dangerous → causation.
  • Higher threshold for “missing safety feature” ADAS litigation. Plaintiffs challenging vehicles for lacking driver-assistance technologies (LDW, lane keeping, lane centering) must first prove the absence makes the vehicle unsafe for normal handling and consumption—mere feasibility, industry trend, or safety enhancement evidence will not alone establish defect.
  • Risk/benefit evidence recalibrated. Litigants can still present alternative-design evidence, but it must illuminate whether the product as sold embodies risks outweighing benefits, rather than functioning as a strict “you should have added feature X” comparative trial.
  • Summary judgment posture. By resolving “no defect” as a matter of law on these facts, Maywald signals that certain design-omission cases (especially where the alleged defect is the absence of technology aimed at preventing driver negligence) may be suitable for early disposition.

4) Complex Concepts Simplified

Strict product liability
Liability focused on the product’s condition, not the manufacturer’s care. But it is not “automatic” whenever someone is injured. Arizona requires proof of defect, unreasonable danger caused by the defect, and causation.
Defective condition (“defect”)
A product characteristic that makes the product unsafe for normal handling and ordinary use (Readenour; Restatement § 402A cmt. h). In plain terms: the product is not reasonably fit for its usual purpose.
Unreasonably dangerous
Even if defective, the product must be more dangerous than consumers would expect or have risks that outweigh benefits (Readenour). This is the limiting concept that prevents strict liability from becoming absolute liability.
Consumer expectation test
Asks whether the product performed as safely as an ordinary consumer would expect when used reasonably (Dart). It is most helpful where consumers have experience with “normal” product performance (often manufacturing defect contexts).
Risk/benefit analysis
A structured balancing of the challenged design’s utility and danger (Dart/Byrns factors). Maywald clarifies the focus is the product as designed and sold, not a direct comparison to an alternative design, though alternative designs can be relevant evidence within the factor list.
Proximate cause
The plaintiff must show the defect actually caused the injury in a legally sufficient way (Rogers; Jimenez). If there is no defect, causation is never reached.
Summary judgment
A pretrial ruling that the moving party wins as a matter of law because there is no genuine dispute of material fact (Ariz. R. Civ. P. 56(a); Rosenberg v. Sanders).

5) Conclusion

Maywald v. Toyota restores clarity to Arizona products liability doctrine by reaffirming that strict liability requires separate proof of (1) defect and (2) unreasonable danger caused by the defect, plus (3) proximate cause. It rejects appellate formulations that collapsed defect and unreasonable danger, disapproves language that blurred the distinction, and confines consumer expectations and risk/benefit balancing to the unreasonable-danger inquiry.

On the merits, the Court held that the absence of LDW in a 2019 Toyota 4Runner did not render the vehicle unsafe for ordinary use and therefore was not a defect, foreclosing strict liability, negligent design, and derivative loss of consortium claims. Going forward, Maywald is likely to be the central Arizona precedent in “missing safety technology” design-omission litigation, especially for advanced driver-assistance features.