Negligence Per Se: Elements, Excuses, Cases and Examples

Negligence per se ("negligence in itself") is a rule that lets a court treat a defendant's violation of a safety statute or regulation as negligence, without the jury deciding what a reasonable person would have done. It applies when the defendant broke the statute without an excuse, the statute was designed to prevent the kind of accident that happened, and the injured person is one of the people the statute was meant to protect.

It settles only one part of a negligence case: breach of duty. The plaintiff still has to prove that the violation caused the injury, and the damages. This guide covers the test, the excuses, the cases that every torts course teaches, and how states split on what a violation actually proves.

The rule

The Restatement (Third) of Torts: Liability for Physical and Emotional Harm § 14 (2010) states it this way:

An actor is negligent if, without excuse, the actor violates a statute that is designed to protect against the type of accident the actor's conduct causes, and if the accident victim is within the class of persons the statute is designed to protect.

The classic statement is Judge Cardozo's in Martin v. Herzog (N.Y. 1920). A man driving a buggy at night without the lights the Highway Law required was killed in a collision with a car, and his widow sued the car's driver. The trial judge told the jury that the husband's missing lights were only "some evidence" of contributory negligence. The Court of Appeals disagreed and directed judgment for the defendant: "We think the unexcused omission of the statutory signals is more than some evidence of negligence. It is negligence in itself."

The elements

1. The defendant violated a statute that sets a specific standard of conduct (a speed limit, a building code requirement). Some states, including New York, treat violations of local ordinances or agency regulations only as evidence of negligence.
2. The plaintiff is in the protected class. The statute was meant to protect people like the plaintiff.
3. The harm is the type the statute was designed to prevent. The accident is the kind of danger the legislature had in mind.
4. No excuse applies. Some violations are excused (below).
5. Causation and damages. The violation, not just the defendant's presence, caused the injury.

Class of persons and type of harm

Elements 2 and 3 do most of the work in exam questions. The usual illustration is Gorris v. Scott (1874), an English case: a shipowner violated a regulation requiring livestock to be kept in pens on deck, and the plaintiff's sheep were washed overboard in a storm. The regulation was meant to stop the spread of disease, not drowning, so the violation did not establish liability.

The American version is Brown v. Shyne (N.Y. 1926). A chiropractor without a medical license treated a patient who was later paralyzed. The court held the licensing statute could not be used to prove negligence, because "the license to practice medicine confers no additional skill upon the practitioner." The patient still had to prove the treatment fell below the standard of skill and care that qualified practitioners exercise. The lack of a license, by itself, did not show that a lack of skill or care caused the injury, and the court ordered a new trial.

Causation still has to be proved

Cardozo made the same point in Martin v. Herzog: "We must be on our guard, however, against confusing the question of negligence with that of the causal connection between the negligence and the injury." A driver without lights pays damages only if the missing lights caused the crash. In Martin itself, a collision more than an hour after sundown with a buggy the driver could not see was evidence from which that causal connection could be inferred.

Excuses

Not every violation counts. The Restatement (Third) recognizes excuses, including where the actor exercised reasonable care trying to comply, where the statute is unclear, and where compliance would have created a greater risk of harm than violation.

The leading case on the last excuse is Tedla v. Ellman (N.Y. 1939). Anna Tedla and her brother were walking along a divided highway on a Sunday evening, wheeling baby carriages loaded with junk, when a car hit them. A statute told pedestrians to keep to the left of the center line, which would have put them on the roadway carrying "very heavy Sunday night traffic." They walked on the other roadway, where there were "very few cars." The defendants argued that the statutory violation barred recovery as a matter of law. The Court of Appeals refused: "We cannot assume reasonably that the Legislature intended that a statute enacted for the preservation of the life and limb of pedestrians must be observed when observance would subject them to more imminent danger."

Worked examples

Example 1: the texting driver

A state statute bans texting while driving. Leah, reading a text, rear-ends Omar at a red light, injuring him.

• Violation: yes.
• Protected class: other road users, which includes Omar.
• Type of harm: collisions caused by distracted driving, exactly what happened.
• Excuse: none.
• Causation: she was looking at her phone instead of the road.

In most states, Leah's breach is established; the trial is about causation and damages.

Example 2: the wrong kind of harm

A city ordinance requires landlords to install smoke detectors. Sam's landlord never installs one. Sam trips over a loose stair and breaks his ankle. The ordinance protects tenants like Sam, but against fire, not falls. The violation does not prove negligence on the stair claim; Sam has to prove ordinary negligence in maintaining the stairs.

Example 3: the excused violation

Rosa crosses a double yellow line to swerve around a child who runs into the road, and clips a parked car. Crossing the line violated the traffic code, but compliance would have meant hitting the child. Like the pedestrians in Tedla, she has a strong excuse.

How states differ

States disagree about what an unexcused violation does.

Approach	Effect of an unexcused violation	Example
Negligence per se, conclusive (most states)	Breach is established as a matter of law	New York, Martin v. Herzog; Restatement (Third) § 14
Rebuttable presumption	Negligence is presumed, but the defendant can rebut it	California Evidence Code § 669
Evidence of negligence	The jury may consider the violation along with everything else	Washington, RCW 5.40.050, with four exceptions

California still calls its rule negligence per se; the California Supreme Court has said Evidence Code § 669 "codifies the common law doctrine of negligence per se." But it works as a presumption: a failure to exercise due care is presumed when the defendant violated a statute, ordinance or regulation, the violation proximately caused the injury, the injury resulted from an occurrence of the nature the law was designed to prevent, and the injured person was in the protected class, and the defendant can then try to rebut it. Washington goes the other way: a breach of a statutory duty "shall not be considered negligence per se, but may be considered by the trier of fact as evidence of negligence," except for four categories: electrical fire safety, smoke alarms, sterilization of needles and instruments in tattooing, body piercing and electrology (and other precautions against the spread of disease), and driving under the influence of alcohol or drugs.

Negligence per se vs. res ipsa loquitur

Both help a plaintiff prove breach without the usual reasonable-person argument, but they start from opposite places. Negligence per se applies when the plaintiff can point to a specific rule the defendant broke. Res ipsa loquitur applies when the plaintiff cannot say what went wrong, but the accident is the kind that ordinarily happens only through negligence.

How it shows up on the exam

• Look for a statute in the facts. A speed limit, a code section or a licensing rule is your cue.
• Argue class and type separately. Most negligence per se questions turn on whether this plaintiff and this harm fall within the statute's purpose.
• Licensing statutes are a trap. Under Brown v. Shyne, a missing license usually proves nothing about care.
• Check for excuses. Emergencies, impossibility and greater danger (Tedla).
• Do not stop at breach. Causation and damages are still the plaintiff's burden (Martin).
• Plaintiffs can violate statutes too. A plaintiff's own violation can be contributory or comparative negligence, as in Martin. See comparative vs. contributory negligence.
• Name the jurisdiction's approach: per se, presumption or evidence.

A short IRAC outline

• Issue: Does the defendant's violation of the statute establish breach?
• Rule: Restatement (Third) § 14: an unexcused violation of a statute designed to protect against the type of accident that occurred, where the victim is in the protected class, is negligence.
• Application: Violation, protected class, type of harm, excuse, then causation.
• Conclusion: Breach established (or presumed, or evidence only, depending on the state), and whether causation is met.

If this happened to you

If you were hurt by someone who broke a safety law (a drunk or texting driver, a landlord ignoring the building code, a business violating safety regulations), negligence per se can make your claim simpler to prove.

• The violation matters, but so does the link. You still need to show the violation caused your injury.
• Keep the paperwork. Police reports, citations and inspection reports can help build your case, though in many states the ticket itself is not admissible in the civil case; a guilty plea sometimes is.
• Your own violations count too. If you were also breaking a rule (jaywalking, say), your recovery may be reduced, or barred entirely if your share of fault is large enough (in most states, 50% or 51%) or, in a few jurisdictions, if you were at fault at all.
• Deadlines apply. Every state has a statute of limitations for injury claims.
• This is general information, not legal advice. A personal injury lawyer licensed in your state can tell you how your state treats statutory violations. Your state or local bar association can usually refer you to one.

How England treats it

England does not use the label. A statutory violation may support a separate tort, breach of statutory duty, but only if the court concludes the statute was intended to give injured people a private right to sue. Gorris v. Scott is an English decision on that tort. Indian law draws on the same English tradition; for the general framework, see our notes on the essential elements of tort.

Related reading

• Res ipsa loquitur
• Comparative vs. contributory negligence
• Essential elements of tort

Sources

• Restatement (Third) of Torts: Liability for Physical and Emotional Harm § 14 (2010), text as quoted in Rogers v. Christina School District, 73 A.3d 1 (Del. 2013); excuses as summarized by Cornell LII, Wex: negligence per se
• Martin v. Herzog, 228 N.Y. 164, 126 N.E. 814 (1920)
• Brown v. Shyne, 242 N.Y. 176, 151 N.E. 197 (1926)
• Tedla v. Ellman, 280 N.Y. 124, 19 N.E.2d 987 (1939)
• Gorris v. Scott (1874) LR 9 Ex 125
• California Evidence Code § 669, as quoted in Elsner v. Uveges, 34 Cal. 4th 915 (2004)
• Revised Code of Washington § 5.40.050