Negligence per se
Breaking a safety law creates a presumption of negligence, which the other side can rebut.
It shifts the argument. Instead of proving what a careful driver would have done, you point at the section they broke. This is general information, not legal advice.
What it means
The presumption applies where someone violated a statute, the violation caused the injury, the injury was the kind the statute was designed to prevent, and the injured person was in the class the statute was meant to protect. All four have to fit.
It is a presumption, not a verdict. It can be rebutted — most obviously by showing the violation was excusable, or that the person did what a reasonable person would have done in the same situation.
This is why the Vehicle Code section an officer records on a crash report matters more than its status as an opinion suggests. It points at the section that will be argued.
Where this is dealt with properly
This entry is the short answer. These pages own the subject.
Common questions
- Does a traffic ticket prove the other driver was negligent?
- Not by itself. The presumption comes from the violation, not the citation, and it can be rebutted. A conviction and a citation are different things again.
Start a case review call
On a case review call, I go through the facts with you: what happened, when, whether you were hurt, whether anyone represents you, and how to reach you. It is not legal advice, and I will not put a value on your claim.
Sources: Evid. Code, § 669 (the presumption and its four elements); CACI No. 418, Judicial Council of California Civil Jury Instructions (2026 edition) (presumption of negligence per se); CACI No. 420 (rebuttal — violation excused). CACI references after the first use the short form.