What is negligence per se?
Negligence per se means that breaking a safety law, like a traffic rule, counts as careless conduct automatically, without arguing over whether the person acted reasonably. The injured person still has to show that the broken rule caused the injury and that real losses followed.
Last checked November 9, 2026 · Official sources (5)
Negligence per se example: a tailgater on the freeway
Example: traffic on a Houston freeway slows suddenly. The SUV behind you is riding two car lengths back at 60 miles an hour and slams into you. Texas law requires drivers to keep an assured clear distance behind the car ahead. Arizona has a similar rule against following more closely than is reasonable and prudent.
Without negligence per se, the two sides might argue about how close is too close. With it, the violation itself can settle the breach question. Say your bills, lost pay and car repairs total $14,000. The claim now turns on whether the crash caused those losses and how much, not on whether tailgating was careless.
How do Arizona and Texas courts treat negligence per se?
| State | What a recent court said |
|---|---|
| Arizona | Negligence per se covers acts that are negligent without further inquiry into whether they were reasonable. In 2025 the Court of Appeals held that breaking the law against letting an unauthorized person drive your vehicle constitutes negligence per se. |
| Texas | Statutory standards define more precisely what breaches the ordinary duty of care. |
Not every law qualifies. Courts usually ask whether the law was written to protect people like you from the kind of harm you suffered. A parking-permit rule, for example, is unlikely to support a crash claim.
Why does negligence per se matter for your claim?
It can make fault far easier to prove, which tends to move adjusters. A ticket, a crash report that cites a statute, or a video of a red-light run all point to a specific law. Write down the statute number from the report and keep the ticket outcome. It does not decide your damages, and a ticket by itself is not a court judgment about your injury claim.
Negligence per se vs. ordinary negligence
Ordinary negligence asks what a reasonably careful person would have done. Negligence per se borrows the answer from a statute. Both still need causation and damages, and both can be reduced by your own share of fault.
Questions
Does a traffic ticket prove negligence per se?
It is strong evidence that a law was broken, but the injury claim is a separate case. The other side can still argue the violation did not cause your injury.
Can negligence per se be used against me?
Yes. If you broke a safety law, such as following too closely, the same idea can increase your share of fault.
Does every broken law count?
No. Courts look at whether the law was meant to protect people like you from the harm that happened.
Find out if you are owed money.
A free case review. $0 upfront. No fee unless you win.
See if I’m owed moneySources (5)
- Kaufman v. Guevara (Ariz. Ct. App. 2025), checked 2026-11-09. “describe[s] those instances where certain acts or omissions constitute negligence without further inquiry [into] the circumstances or reasonableness of their occurrence.”
- City of Houston v. Manning (Tex. 2025), checked 2026-11-09. “the statutory standards of care used to measure negligence per se “merely [] define more precisely what conduct breaches” the “common law duty,””
- Tex. Transp. Code § 545.062, checked 2026-11-09. “maintain an assured clear distance between the two vehicles”
- A.R.S. § 28-730, checked 2026-11-09. “shall not follow another vehicle more closely than is reasonable and prudent”
- Kaufman v. Guevara (Ariz. Ct. App. 2025), checked 2026-11-09. “The primary question before us is whether violating that law constitutes negligence per se. Because we answer the question affirmatively”