Negligence Per Se

Negligence per se is a doctrine that substitutes a legislative or regulatory standard for the common law reasonable person standard of care. When a defendant violates a statute, and the plaintiff falls within the class of persons the statute was designed to protect, and the harm suffered is the type the statute was designed to prevent, the statutory violation establishes breach of duty as a matter of law.

The rationale is straightforward: the legislature has already determined the appropriate standard of conduct, and it would be inconsistent for courts to allow a lower standard. If a traffic statute prohibits running red lights to protect drivers and pedestrians from collisions, a driver who runs a red light and strikes a pedestrian has breached the statutory standard of care. The plaintiff need not separately prove that the driver's conduct fell below the reasonable person standard.

Jurisdictions differ on the effect of a statutory violation. In some, the violation is conclusive proof of negligence (negligence per se in the strict sense). In others, it creates a rebuttable presumption of negligence. In still others, it is merely evidence of negligence that the jury may consider.

Even when negligence per se establishes breach, the plaintiff must still prove the remaining elements of a negligence claim: duty, causation (both actual and proximate), and damages. The statute substitutes only for the breach element. Additionally, certain excuses may defeat negligence per se, including incapacity, lack of knowledge of the need to comply, inability to comply despite reasonable diligence, and emergency situations.

On exams, negligence per se appears whenever a defendant violates a statute. The key analysis is whether the plaintiff is within the protected class and the harm is within the type of risk the statute addresses.