Glossary
Negligence per se
Breaking a safety law, such as a traffic or trucking rule, that was meant to prevent the kind of harm that happened. In many states it proves negligence or strongly points to it.
General information, not legal advice. Talk to a licensed attorney in your state.
Quick answer
Negligence per se applies when someone breaks a safety law, such as a traffic or trucking rule, that was meant to prevent the kind of harm that happened. In many states it proves Negligence. Failing to use the care a reasonable person would use in the same situation, such as running a red light or texting while driving. Glossary, or strongly points to it, without arguing over what a careful driver would have done.
In a car accident claim#
The rule usually needs three things: the law was meant to protect people like the injured person, it was meant to prevent this kind of harm, and breaking it caused the harm. Traffic laws are the classic example. Florida, for instance, requires a driver passing a bicycle in the same lane to leave not less than 3 feet. A driver who clips a cyclist while passing closer may be treated as negligent under this rule.
Trucking rules work the same way. Federal hours-of-service rules let a truck driver drive at most 11 hours after a required rest period, and a crash by a driver over that limit can support a negligence per se argument. States differ on the effect: in some it settles negligence unless there is a valid excuse, such as when obeying the law would have been more dangerous; in others it only points to negligence. The injured person still has to prove Causation. The link between someone's careless act and your injury. You must show the crash caused the harm you are claiming. Glossary and damages. Our guides to truck accidents and bicycle accidents give more examples.
Example#
Related terms#
Questions people ask
Does a traffic ticket prove negligence per se?
Not on its own. The question is whether the driver actually broke the law and whether that caused the crash. States have different rules on whether a ticket or a guilty plea can be used in the civil case.
Is negligence per se the same as strict liability?
No. Negligence per se uses a broken safety law to show carelessness, and the injured person still must prove causation and damages. Strict liability makes someone responsible without proof of fault, in a few specific situations.
Sources
- Cornell LII Wex, Negligence per se — elements and excuses
- Florida Legislature, Florida Statutes § 316.083 — passing distance for bicycles
- FMCSA, Summary of Hours of Service Regulations — driving limits for truck drivers
Last reviewed October 29, 2026 by the Accident Claim Facts editorial team. Found an error? Tell us.
Keep reading
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- GlossaryNegligenceFailing to use the care a reasonable person would use in the same situation, such as running a red light or texting while driving.
- GlossaryNon-economic damagesLosses without a price tag, such as pain, suffering, emotional distress and loss of enjoyment of life.
- GlossaryNotice of claimA written notice that must be sent to a city, county or state agency before you can sue it, often within a few months.