How Fault and Liability is Determined in a Car Accident

When car accidents are discussed legally, the first thing that should be discussed is fault and liability. Since most car accidents are settled out of court, insurance companies take on the main role of determining fault. 

Read on to see a general overview of how insurance companies determine who is at fault in a crash.

How do insurance companies determine fault?

A lot goes into the process of determining fault, but a big part of it depends on where the accident occurred. States either operate on at-fault or no-fault car insurance laws and have different definitions for the other factors involved. 

Below are the seven main factors that insurance companies keep in mind in determining who to hold liable for the accident.

At-fault versus no-fault accidents

Fault-based accidents occur in tort states, which are states that don’t require drivers to add personal injury protection coverage for their car insurance

In tort states, insurance companies will investigate the accident and hold the driver found responsible for causing the accident financially responsible for all the damages. This includes both medical expenses and property damage costs.

States that have a no-fault system require all drivers to purchase car insurance with personal injury protection to cover medical expenses in case of accidents, regardless of who was at fault. 

In this case, all parties involved have to pay for ambulance expenses, emergency room costs, and the subsequent medical bill with their personal injury protection coverage. However, the party at fault has to cover all property damages.


When investigating who was at fault, insurance companies commonly use applicable state laws that define negligence. If you’re involved in a car accident, and you need additional help proving negligence, it helps to strengthen your insurance company’s case and hire an attorney who cares about you, not just results

You’ll need all the legal help you can get because the way a state interprets negligence will dictate how fault is determined and the subsequent claims.

Contributory or pure negligence

If a state uses contributory or pure negligence, you are not allowed to receive insurance payouts if you were found negligent in any way that contributed to the car accident. Whether you were mainly at fault or responsible for only a small percentage of the accident doesn’t matter.

Comparative negligence

States that use comparative negligence allow parties to recoup accident-related expenses from the other party based on their percentage of responsibility for the accident. Each party is assigned a degree of fault responsibility, which determines the amount of compensation a given party will receive. 

For example, if one party was found 60% negligent, their insurance company will cover 60% of the other party’s medical expenses and property repair bills. The remaining 40% will be taken care of by the other party’s insurance company.

Modified comparative negligence

Modified comparative negligence sets a limit in assigning the degree of fault to both parties. If they found one party to be more than 50 or 51% percent at fault, they cannot recover any expenses from the other party. 

States that use this definition require both parties to pay for their medical expenses or repair bills, even if one party was partially at fault.

Evidence and police reports

Evidence and police reports

To determine negligence, insurance companies will rely on objective elements such as evidence, police reports, and eyewitnesses. Police reports and witnesses fill out all the necessary details needed to get a complete picture of the accident. 

Evidence gathered from the scene is imperative in determining who was at fault. In proving that the other party was being a negligent driver, the insurance company may investigate the following:

  • A negligently maintained vehicle (knowingly operating a defective car)
  • Phone records to prove driving and texting
  • A poorly adjusted seat
  • Driving while intoxicated

Environment and road conditions

Environment and road conditions

Additionally, the environment also plays an integral part in finding out why the accident happened in the first place. Inclement weather, especially snow or sleet storms, is one of the most common culprits for driving-related accidents because of the slippery roadways.

Poor road conditions such as faulty construction, unleveled lanes, confusing street signages, and the lack of hazard warnings can bring other parties at fault. In this case, the parties involved are also entitled to take legal action against the agencies or entities responsible for maintaining the road.

What can you do?

Insurance companies are your first line of defense in determining fault in a car accident. However, if you feel like they’re not doing enough, you may need additional help. What can make a big difference is seeking legal counsel from seasoned car accident lawyers.

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John Miller

John Miller is a cars enthusiast who loves writing anything related to automobiles. He is a passionate blogger writing for and other auto blogs