Negligence Per Se in Illinois: When Breaking a Law Proves Negligence Automatically

What Happens When the At-Fault Party Broke a Law

In a standard personal injury case, you have to prove that the other party was negligent. You must show they owed you a duty of care, breached that duty, and caused your injuries. This can involve extensive evidence and expert testimony.

But what if the person who hurt you was breaking a law at the time? In Illinois, that can simplify your case dramatically through a doctrine called negligence per se.

What Is Negligence Per Se?

Negligence per se means “negligence in itself.” It is a legal shortcut. When someone violates a statute or ordinance, and that violation causes the type of harm the statute was designed to prevent, the violation itself is treated as proof of negligence.

You do not have to separately prove that the person failed to act reasonably. The law already defined what reasonable conduct looks like. They broke that law. That is enough to establish the duty and breach elements of a negligence claim.

The Illinois Supreme Court has recognized negligence per se in numerous decisions. The doctrine is well-established in Illinois law, though it has specific requirements that must be met.

The Four Requirements for Negligence Per Se in Illinois

Not every statutory violation qualifies for negligence per se. Illinois courts require four elements:

1. The defendant violated a statute, ordinance, or regulation. The law in question must be a specific legal requirement, not a general guideline.
2. The plaintiff is a member of the class of persons the statute was designed to protect. The law must have been enacted to protect people like you.
3. The harm suffered is the type of harm the statute was designed to prevent. If a traffic law is designed to prevent collisions, and you were injured in a collision caused by the violation, this element is satisfied.
4. The violation was the proximate cause of the injury. The statutory violation must have actually caused or contributed to your injury. A violation that had nothing to do with the accident does not trigger negligence per se.

Common Examples in Personal Injury Cases

Traffic Violations and Car Accidents

This is the most common application of negligence per se in Illinois. The Illinois Vehicle Code (625 ILCS 5) sets rules for driving behavior. When a driver violates these rules and causes an accident, negligence per se often applies.

Examples include:

• Running a red light (625 ILCS 5/11-306)
• Speeding (625 ILCS 5/11-601)
• Failing to yield the right of way (625 ILCS 5/11-901)
• Driving under the influence (625 ILCS 5/11-501)
• Texting while driving (625 ILCS 5/12-610.2)
• Following too closely (625 ILCS 5/11-710)

If a driver runs a red light and hits your car, the red light violation is negligence per se. You still need to prove causation and damages, but you do not need to argue about whether running a red light is “unreasonable.” The law already says it is.

For more on car accident claims in Illinois, visit our dedicated page.

Building Code Violations

Property owners must comply with building codes and safety regulations. If a building code requires handrails on stairs and a landlord fails to install them, and you fall and get hurt on those stairs, the building code violation can establish negligence per se.

Chicago has its own municipal code with extensive building safety requirements. Violations of the Chicago Municipal Code can also support negligence per se claims.

Trucking Regulation Violations

Federal Motor Carrier Safety Regulations (49 CFR) set rules for commercial trucks, including hours-of-service limits, maintenance requirements, and cargo securement standards. When a trucking company violates these federal regulations and causes an accident, negligence per se may apply.

For example, if a truck driver exceeded the maximum consecutive driving hours (11 hours under federal rules) and fell asleep at the wheel, the hours-of-service violation is strong evidence of negligence per se.

DUI Accidents

Driving under the influence is illegal under 625 ILCS 5/11-501. A DUI arrest or conviction can be used to establish negligence per se in a civil personal injury case. This is particularly powerful because it removes the need to argue about whether the drunk driver was being “reasonable.” Driving drunk is illegal, period.

Negligence Per Se vs. Regular Negligence

Here is the practical difference:

Regular negligence: You must prove (1) the defendant owed you a duty of care, (2) the defendant breached that duty by acting unreasonably, (3) the breach caused your injury, and (4) you suffered actual damages.

Negligence per se: The statute defines the duty and the breach. You only need to prove (1) the statutory violation, (2) you are in the protected class, (3) the harm is the type the statute prevents, and (4) causation and damages.

The first two elements of negligence (duty and breach) are essentially proven by the statutory violation alone. This saves time, simplifies the case, and makes it harder for the defendant to argue they acted reasonably.

Does Negligence Per Se Guarantee You Win?

No. Negligence per se establishes that the defendant was negligent. It does not automatically mean you win the case. You still must prove:

• Causation. The statutory violation must have actually caused your injury. A driver who was speeding but whose speed had nothing to do with the collision (perhaps the accident was caused by an icy road) may not be liable under negligence per se for the speeding.
• Damages. You must prove you suffered actual harm and quantify your losses.

The defendant can also raise defenses, including comparative fault. Under Illinois modified comparative fault law, if you are found to be 50% or more at fault, you recover nothing. The defendant’s statutory violation does not immunize you from your own negligence.

Learn more about how shared fault works on our page about both drivers sharing fault in Illinois.

Can the Defendant Argue the Violation Was Justified?

In some cases, yes. Illinois courts recognize limited excuses for statutory violations. A defendant might argue:

• The violation was necessary to avoid a greater harm (emergency doctrine).
• The defendant was physically incapacitated (such as a sudden medical emergency).
• The defendant did not know and could not reasonably have known about the condition requiring compliance.

These defenses are narrow and fact-specific. A defendant who ran a red light because they were having a heart attack might have a valid excuse. A defendant who ran a red light because they were late for work does not.

Criminal Convictions as Evidence

If the at-fault party was convicted of a traffic violation or crime related to the accident, that conviction can be used as evidence in your civil case. A DUI conviction, for example, is strong evidence supporting a negligence per se argument.

However, a traffic ticket that was dismissed or a charge that was reduced may not carry the same weight. The admissibility of criminal case outcomes in civil proceedings depends on the specific circumstances.

Negligence Per Se in Motorcycle Accident Cases

Motorcycle accident cases often involve drivers who violated traffic laws. Common violations include failing to check mirrors before changing lanes, turning left in front of an oncoming motorcycle, and opening a car door into a motorcycle’s path.

Negligence per se is particularly valuable in motorcycle cases because juries sometimes have biases against motorcyclists. Establishing the other driver’s negligence through a clear statutory violation removes the subjective “reasonableness” argument and focuses the case on the law that was broken.

How Insurance Companies Respond to Negligence Per Se

When the at-fault party clearly violated a statute, insurance companies know they are in a weaker position. They may be more willing to settle rather than go to trial, where a jury instruction on negligence per se would be powerful.

That said, insurers will still fight on causation and damages. They may argue that even though their insured violated a law, the violation did not cause your specific injuries. Or they may argue your injuries are not as severe as you claim.

Building Your Negligence Per Se Case

To take advantage of negligence per se, you need:

• The police report. If the officer cited the other driver for a violation, that citation supports your negligence per se argument.
• The specific statute or ordinance. Your attorney needs to identify the exact law that was violated and show it meets the four requirements.
• Evidence of the violation. Dashcam footage, traffic camera footage, witness statements, and expert testimony can all prove the violation occurred.
• Medical records. You still need to prove your injuries and connect them to the accident.

Why Legal Representation Matters

Negligence per se is a legal doctrine with specific requirements. An attorney who understands Illinois tort law can identify applicable statutes, argue for negligence per se jury instructions, and use the doctrine to strengthen your case. The right lawyer knows how to leverage this powerful tool.

Talk to Phillips Law Offices Today

If you were injured because someone broke a law in Illinois, you may have a strong negligence per se claim. Do not let the insurance company talk you out of what you deserve.

Call Phillips Law Offices at (312) 346-4262 or contact us online for a free consultation.