## Facts

- Paul and Jill Rhoads bought a new ATV and received written safety warnings, including a warning to wear a helmet.
- The next day, they hosted a party and permitted guests to ride the ATV on their property.
- Charles Stehlik, an adult guest with prior riding experience, consumed alcohol, became intoxicated, and chose to ride the ATV without a helmet, though helmets were available.
- Stehlik drove the ATV over an embankment; the ATV rolled; he struck his head on a concrete retaining wall and suffered serious head injuries.
- Stehlik sued the Rhoads for negligence and negligent entrustment, alleging they allowed intoxicated and unhelmeted ATV operation and failed to require helmet use.
- Stehlik stipulated that if he had worn a helmet, he would not have sustained any serious head injury.
- A jury found both sides negligent, set total damages at about $853,277, and reduced the award to about $54,198 using comparative negligence and a separate reduction tied to helmet nonuse.
- The trial court permitted a “helmet defense” and entered judgment on the reduced amount; the case reached the Wisconsin Supreme Court after certification.

## Issues

1. Whether the “helmet defense” is governed by the same principles as Wisconsin’s seat belt defense, and how it affects admissibility and use of helmet-nonuse evidence.
2. Whether an ATV owner can be liable for failing to require adult riders to wear a safety helmet.
3. Whether the jury instructions and verdict form improperly conflated accident causation with injury enhancement and improperly applied comparative fault and damage reduction.

## Decision

- The Wisconsin Supreme Court reversed the judgment and remanded.
- Helmet nonuse is treated like seat belt nonuse: it is relevant to mitigation of damages (injury enhancement), not to comparative negligence for causing the accident.
- Evidence of helmet nonuse is admissible only to prove the extent to which injuries would have been reduced or avoided had a helmet been used, supported by competent proof (here, the stipulation supplied that causal link).
- ATV owners may, under ordinary negligence principles, have a duty to act reasonably regarding foreseeable risks of unhelmeted riding by adults, but the duty is fact-dependent and not absolute.
- The trial court erred by failing to clearly separate (a) negligence causing the rollover from (b) conduct affecting only the severity of injuries, allowing the jury to treat helmet nonuse as part of general contributory negligence and risking double counting.

## Legal Principles

- Wisconsin’s seat belt doctrine governs helmet nonuse: protective-device nonuse that affects only injury severity is a damages-mitigation issue, not a basis to assign fault for accident causation.
- Courts must distinguish accident causation from injury enhancement; only the former belongs in comparative negligence apportionment of fault.
- A plaintiff’s failure to use available safety equipment may reduce recoverable damages only to the extent competent evidence shows the injuries would have been prevented or lessened.
- A property owner/entrustor’s duty to adult users is evaluated under ordinary negligence (reasonable care under the circumstances), including foreseeability and the adult user’s ability to appreciate and avoid the risk.
- Helmet nonuse should not be counted twice—once as comparative negligence for the accident and again as a damages reduction for injury enhancement.

## Conclusion

The court required helmet nonuse to be handled solely as injury-mitigation evidence (analogous to the seat belt defense) and held that any owner duty to require helmets for adult riders depends on ordinary negligence standards; because the jury instructions blurred accident fault with injury enhancement, the judgment was reversed and the case remanded.


Stehlik v. Rhoads, 645 N.W.2d 889 (Wis. 2002)