California Evidence Code § 669 EC defines negligence per se as failing to exercise due care by violating a law (such as a traffic ordinance), which results in property damage or physical injury.
Plaintiffs who sue on negligence per se grounds do not have to prove that the defendant failed to exercise due care: The court can presume it unless the defendant successfully rebuts the presumption.
The text of the statute reads:
EC 669. (a) The failure of a person to exercise due care is presumed if:
(1) He violated a statute, ordinance, or regulation of a public entity;
(2) The violation proximately caused death or injury to person or property;
(3) The death or injury resulted from an occurrence of the nature which the statute, ordinance, or regulation was designed to prevent; and
(4) The person suffering the death or the injury to his person or property was one of the class of persons for whose protection the statute, ordinance, or regulation was adopted.
(b) This presumption may be rebutted by proof that:
(1) The person violating the statute, ordinance, or regulation did what might reasonably be expected of a person of ordinary prudence, acting under similar circumstances, who desired to comply with the law; or
(2) The person violating the statute, ordinance, or regulation was a child and exercised the degree of care ordinarily exercised by persons of his maturity, intelligence, and capacity under similar circumstances, but the presumption may not be rebutted by such proof if the violation occurred in the course of an activity normally engaged in only by adults and requiring adult qualifications.
Under California Evidence Code 669, courts will presume that defendants in personal injury cases failed to exercise due care ( were “negligent per se”) if:
- the defendant violated a law or regulation;
- This violation caused the plaintiff to sustain an injury or property damage; and
- The law that the defendant violated was meant to protect people like the plaintiff.
Example: Jay is going 70 mph on a 35 mph road when he crashes into Pam, who was not speeding. Pam sues Jay for negligence per se.
The speeding ordinance is meant to protect drivers on the road, such as Pam. Since Jay violated the speeding law by going twice the limit, the court can presume that Jay failed to exercise due care towards Pam. If the court finds that Jay’s speeding caused Pam’s injuries, he will be held liable for the accident.
Note that defendants sued for negligence per se can try to rebut the presumption that they failed to exercise due care by showing that a reasonable person would have acted in a similar way under the circumstances.1
Example: Max is driving when he sees a power line on the ground. He quickly swerves to avoid driving over the live wire, but he sideswipes Sandy in the process.
If Sandy sues Max for negligence per se, Max can try arguing that he had no time to signal and that anyone in his position would have changed lanes to avoid being electrocuted. This could potentially rebut the presumption that Max failed to exercise due care towards Sandy.