## Facts

- Bert Marolla, a railroad employee, operated a motorized railroad track car on tracks approaching a public road crossing.
- Wayne Hetzer drove an automobile insured by American Family Mutual Insurance Company toward the same crossing; the vehicles collided at approximately right angles within the crossing.
- The railroad maintained an internal safety rule for track-car operators at public crossings: approach under “complete control” and “stop if necessary.”
- Evidence also existed of an internal employee custom consistent with the rule regarding how to handle track cars at crossings.
- Marolla sued American Family for personal injuries and related losses; American Family counterclaimed for amounts it paid for damage to Hetzer’s automobile.
- The trial court excluded the railroad’s internal safety rule and excluded or tightly limited evidence of the internal custom offered to show Marolla’s contributory negligence.
- The jury apportioned negligence 75% to Hetzer and 25% to Marolla and awarded damages to Marolla; judgment was entered accordingly.

## Issues

1. Whether a private employer’s internal safety rules are admissible in a negligence action to establish the legal standard of care or to be considered as evidence bearing on comparative negligence.
2. Whether evidence of an internal workplace custom consistent with such rules is admissible to assess the plaintiff’s comparative negligence.
3. Whether excluding the rule and custom evidence was prejudicial error requiring a new trial or reversal.

## Decision

- The Wisconsin Supreme Court affirmed the judgment for Marolla.
- The court held that private safety rules do not set or alter the legal standard of ordinary care owed to others.
- The court recognized that internal rules and customs may, in appropriate circumstances and with limiting instructions, be admissible as some evidence bearing on due care.
- On this record, exclusion of the railroad’s rule and related custom evidence was not shown to be prejudicial; the verdict was supported by credible evidence and the apportionment of negligence stood.

## Legal Principles

- The legal standard of care in negligence is fixed by law (statutory or common); private rules cannot raise or lower that duty.
- Internal safety rules and workplace customs may be relevant and admissible as evidentiary facts bearing on whether conduct was careful, but they are not dispositive and cannot be treated as the governing standard.
- Reversal for exclusion of private rule/custom evidence requires a showing of prejudice; exclusion is harmless when the verdict is supported by credible evidence and the excluded matter would not change the governing ordinary-care standard.

## Conclusion

The court upheld a comparative-negligence verdict for an injured railroad employee, ruling that employer safety rules and internal customs do not define legal duty and that their exclusion, in this case, did not materially affect the outcome.


Marolla v. Am. Fam. Mut. Ins. Co., 38 Wis. 2d 539, 157 N.W.2d 674 (Wis. 1968)