How to determine who is at fault in a collision: a guide

Sometimes it's clear and sometimes it's not. Like most things in life, gray areas exist when it comes to determining who's to blame in a car accident.

The intricacies of assigning fault are highly subjective — practices vary by state and by the insurance company, so the specifics of your policy really matter. Read on to explore different scenarios in which determining fault can get a little murky.



1. What does "fault" mean in insurance?
2. No-fault states vs. tort states
3. FAQs



What does "fault" mean in insurance?

It sounds easy enough — who was the perpetrator of the accident? If you're rear-ended because someone failed to stop in time, the fault of the other driver is much more clear-cut than a situation in which blame could go either way. After a collision in which both — or multiple — drivers are pointing fingers at one another, things can get complicated.

It's the job of the insurance company to determine who or what caused the wreck so they can determine who pays. But at the same time, every insurer handles coverage and claims differently, and each U.S. state has its own laws about what car insurance must cover and how fault is defined and determined. Insurance is never quite as simple as you may think!


No-fault state vs. tort state insurance laws

As mentioned above, insurance laws are state-based. Some states are "no-fault" states and the rest are "tort" states:

  • In no-fault states, each driver turns to his or her own auto insurance for coverage for medical expenses no matter who caused the crash.
  • In tort states, insurers conduct an investigation into who caused the crash, and car insurance companies pay for damages based on who is found at fault. Drivers sometimes have to sue the other party for damages in tort states.

Most states are tort states. Just 12 states have no-fault coverage, and three of them (Kentucky, New Jersey and Pennsylvania) give drivers the choice of either tort or no-fault coverage.

In the remaining nine (Florida, Hawaii, Kansas, Massachusetts, Michigan, Minnesota, New York, North Dakota and Utah) there is no such choice — drivers must carry no-fault coverage.



How does “no-fault” work in auto insurance scenarios?

Drivers insured in “no-fault” states are often confused when they're involved in a wreck since the term is somewhat misleading. “No-fault” only refers to injuries, not to property damage. So, if you cause a wreck in a no-fault state, the other driver’s insurance will cover their injuries, but your insurance is still on the hook for property damage (including damage to your vehicle), which is covered under liability. If you’re injured in that same wreck, your insurance will cover your bodily injury (and that of your passengers), but it’ll only cover damage to your vehicle if you’ve purchased additional comprehensive and collision coverage, which is often called “full coverage” — a term which is something of a misnomer.

Who determines fault in a collision?

Fault is determined by the adjuster assigned to each incident and the state in which the crash occurred. There isn’t an exact set of standards or requirements to determine fault across the board in the U.S.

How is fault determined?

Insurance companies assess the damage and review the events preceding the wreck. They gather information from both parties (or, all parties if the wreck involves more than two vehicles), and any available witnesses. The insurance companies then attempt to determine who caused the collision. Based on the decision, an insurance company is handed the responsibility of paying for injuries and damages.

The degree of fault is another complication. If you were merging onto a highway while another driver is attempting to exit and there is a wreck, both parties could be considered partially liable for the crash. So, your insurance company might agree to 70% of the damages, while the other driver’s insurance might take the remaining 30%. Comparative fault helps insurers because they often share the burden of a claims payout rather than suffering the full cost of the damage.

Split or shared liability (fault) varies by state, and some states consider a driver who is 51% or more “at fault” to be 100% liable for damages. In most states, if both parties are considered 50% liable then they are both considered to be at fault and would need to be covered by their own policy in most cases.

What happens if fault is unclear in a car collision?

If it’s difficult to prove fault, insurance companies will sometimes split the cost of damages 50-50 (if the state allows). Say two cars are involved in a wreck in an intersection. Unless there are witnesses, it can be very difficult to prove who had the red light and who had the green. This is one reason why witnesses are so important — if you don’t have them, both parties can claim they had the green.

If I’m injured in a collision caused by another party in a no-fault state, is there an instance in which the other person’s insurance would pay?

Yes. Your insurance pays the primary costs, but if your medical expenses exceed the coverage limits of your policy (called Personal Injury Protection coverage, which is usually about $10,000), the other party’s liability insurance will kick in.

So, even in no-fault states, if there’s bodily injury after a crash, the insurance companies still must determine fault. If you’re injured but also at fault, you can’t go after the other driver’s coverage if you exceed your own. There is also a stipulation in the law in “no-fault” states that would allow for a person to sue another driver for “pain and suffering” depending on the threshold allowed in those particular states. Pain and suffering are not covered under PIP.

Aside from coverage, what other differences exist between no-fault and tort states?

The Zebra’s State of Auto Insurance report shows that in many of the no-fault states, insurance is more expensive than in tort states.

Fraud rates also differ between no-fault and tort states. Florida, Michigan, and New Jersey have a lot of fraud with PIP coverage because the coverage limits in those states are substantial, and therefore auto insurance tends to be much more expensive in these states. In Florida, there’s a $10,000 PIP coverage limit, but in New Jersey, the limit is between $15,000 and $250,000, and Michigan doesn’t even have a limit, raising the potential for an ill-gotten windfall.

In a state that does use fault for bodily injuries, it’s hard to go after someone else’s auto insurance for a fake injury. It still happens, but it’s more difficult.

How do insurance companies determine the “degree of fault” if multiple vehicles are in a crash?

With a multi-car pileup, fault varies significantly based on the details of the crash and the state. There isn’t exactly a broad explanation of how fault is determined in those situations.

How does fault work when a driver hits an object (or an animal) and not another vehicle?

If you hit something stationary, it’s considered a crash, and you would have to have collision coverage on your policy to be covered. A few examples: a pothole, wood or a tree limb, a piece of machinery that fell off a truck, and roadkill. As far as the insurer is concerned, it’s your responsibility to avoid hitting inanimate objects.

However, if you hit a living, moving animal, or a moving inanimate object hits you (like rubber from an exploded truck tire), you can make a claim if you have comprehensive coverage on your policy. In the eyes of the insurer, since the animal (or road debris) was moving, you couldn’t have been expected to know where it would go, and so it isn’t your fault for hitting it. If you don’t have comprehensive and collision coverage, you’ll have to pay for property damages out of pocket.

Most people carry both comprehensive and collision coverage (if they decide they want optional coverage in case their vehicle is damaged). You can carry comprehensive coverage on your policy without adding collision, but you can’t carry collision without comprehensive in the majority of cases. Since collision coverage is normally much more expensive, some people will leave it off their policy (though people with loans are required to have collision coverage). But, people who still want their vehicles to be covered against theft, vandalism, fire, flooding, and animals should add comprehensive coverage. This means that if this person wrecks his car (by hitting roadkill, or another stationary object in the road, for example) then he has no coverage to get it repaired, but if this person happens to collide with a living deer in the road, then the damage would be covered under comprehensive.

Kristine Lee
Kristine Lee LinkedIn

Kristine is a licensed insurance agent and one of The Zebra’s in-house content strategists. With a background in copywriting, she covers the ins and outs of the home and car insurance industries. She has contributed to numerous publications focused on the nuances of insurance, including Automoblog,, and

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Recent Questions:

How does a not-at-fault accident appear on my driving record

Most driving records insurance companies run will show the claim paid under "no fault" or "not-at-fault" and should not affect your rates at all. If your current car insurance quote reflects the accident as "at-fault," present the evidence you have in your favor and get a new quote.

Who is at-fault when parking spot stopper had bolts sticking out of it?

Unfortunately you would be considered at fault for the damage to your vehicle. If you file a claim, it will likely be paid under collision coverage, meaning you'll be required to pay your deductible.

I was rear-ended so how I am at-fault?

I recommend contacting whichever insurance company insurers the vehicle and speak with them. Fault can only be determining by claims adjusters, not the other driver or even police.

Who is at fault in a multi car rear end accident

In a multi-car crash, fault is extremely difficult to determine so I can't tell you with any certainty if you will be held responsible for any damage. I will say that fault can be spread to multiple drivers in these situations (called comparative fault or negligence), but ultimately, fault will have to be determined by the insurance adjuster(s) handling the claim.