How Is Fault Determined in a Car Accident?

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Insurance companies consider multiple factors when determining fault in a car accident, including reported details of the accident, each driver's negligence and traffic camera footage providing evidence of liability. In some cases, multiple drivers are partially responsible for causing an auto accident, and insurance companies may assign a percentage of fault to each driver. Determining fault in a no-fault state is less of a consideration, as each driver's insurance company will pay for damages and losses, regardless of who is at fault.

Keep reading to learn how car insurance companies determine fault and how coverage works when you're the at-fault driver.

How Insurance Companies Determine Who's at Fault in Car Accidents

When you and the other driver report a car accident to your respective insurance companies, each insurance company will typically investigate the claim to determine who is at fault. Generally, the adjusters will review the accident details and camera footage, read the police report and contact eyewitnesses to determine if one or both drivers were acting negligently.

Driving violations can result in a citation, points on your driving record, the suspension of your driving privileges and possible imprisonment.

Accident Details

If you committed a driving infraction, you likely hold at least some responsibility for causing the accident. Some driving violations the adjusters factor in include:

  • Rear-ending the other driver's car: Generally, the driver who rear-ends a car is at-fault for the accident, especially if the other driver was stopped at a red light.

  • Driving under the influence: Driving while inebriated from alcohol or drug consumption can severely impair your ability to drive. You can expect to be assigned the majority of responsibility for causing the car accident.

  • Disregarding traffic rules and signals: Not obeying traffic laws, such as running a red light or stop sign or failing to yield to drivers with the right of way, is high-risk behavior that can lead to car accidents. Some intersections have traffic cameras that insurance carriers can use to prove negligence.

  • Driving while distracted: Texting behind the wheel isn't the only form of distracted driving — be eating, drinking or setting your GPS while driving can render you liable for an accident.

Keep in mind that many of the offenses above are driving violations, which can result in a traffic citation, points on your driving record, the suspension of your driving privileges and possible imprisonment.

Supplemental documentation and testimonies

Both the other driver and your adjuster may investigate the claim, compiling evidence to determine the level of negligence for each driver. This often includes reviewing police reports, obtaining video footage, interviewing eyewitnesses and taking testimonials.


Fault can be shared among multiple drivers if multiple drivers were acting negligently. Consider the following scenario:

  1. Driver A T-boned Driver B at an intersection.

  2. Driver A ran a red light.

  3. Driver B was speeding.

In an accident, it may be determined that Driver A was acting 80% negligent for running a red light and Driver B was acting 20% negligent for speeding. The level of negligence apportioned to you can dictate how much of a claim settlement you may be entitled to.

There are three types of negligence that states use: comparative, modified comparative and contributory negligence.

Comparative Negligence

If you and the other driver are both responsible for causing the accident, you both share the cost of damages in proportion to each driver's percentage of fault.

Example: You are 40% at fault and the other driver is 60% at fault. Your medical bills total $1,000. The other driver would pay $600 (60%) and you would the remaining $400 (40%). Similarly, you would pay 40% of the other driver's expenses.

Modified Comparative Negligence

The driver who is 51% at fault for an accident cannot seek compensation from the other driver. If negligence was split 50/50, each driver would pay half of the other driver's losses.

Example: You are 51% at fault and your medical bills total $1,000. You cannot seek compensation from the other driver even if they are 49% at fault.

Example 2: You and the other driver are 50% responsible for causing the accident. Your expenses total $1,000 and the other driver's expenses total $1,500. The driver would pay you $500 for your damages and you would pay the other driver $750 for their damages.

Contributory Negligence

If you hold any responsibility at all for causing the accident, then you cannot recoup expenses from the other driver.

Example: You hold just 1% fault for causing the accident. Neither you nor the other driver can seek to recoup expenses because you were both at fault for the accident.

Disputing your portion of negligence

If you disagree with the level of negligence apportioned to you, you may attempt to negotiate a better deal with the other insurance company. Otherwise, you may sue the at-fault driver and have a judge review the details to make a final decision on each driver's apportionment of negligence.

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Determining Fault in Tort States vs. No-fault States

Determining fault works differently in tort states versus no-fault states. In tort states, adjusters will investigate the claim to determine who was responsible for the accident by reviewing the accident details, reading the police report and interviewing eyewitnesses. In no-fault states, no investigation is needed to fulfill a claim — instead, insurance companies will cover their own policyholders, regardless of who is at fault.

Below, we highlight key differences between tort states and no-fault states.


No-Fault State

Tort State

Determining Fault

Determining the fault (or level of fault) is not necessary for the claims process.

Insurance companies investigate the accident to determine which driver(s) were responsible for the accident.

Financial Liability

Each driver is reimbursed by their own insurer, whether the accident was the other driver's fault or yours.

The at-fault driver (or whoever was most at-fault) is responsible for covering the other party's medical bills.

Right to Sue

Drivers can only sue the at-fault driver in a small claims court for severely extensive or costly injuries.

No limits to filing a lawsuit against the at-fault driver.

Determining fault works differently in tort states versus no-fault states.

Does Car Insurance Cover At-fault Accidents?

Depending on your policy, several types of coverage can come into play when you are the at-fault driver in an auto accident.

Bodily injury liability

Bodily injury liability coverage pays for the injured party's healthcare services for bodily injuries, death benefits and more to the other injured parties (excluding yourself and family members) when you are the at-fault driver in a car accident. Covered expenses may include the other driver's emergency services, medical equipment, like a wheelchair or crutches or death benefits. Your bodily injury liability coverage may also pay for legal fees if you are sued.

Property damage liability

Property damage liability covers the other driver's repair costs, including labor and replacement parts, to their vehicle other property when you are responsible for causing the accident. Your insurance company may also cover damaged non-vehicle property, such as fences, business storefronts and mailboxes. Defense fees are also covered if you are sued by the other driver.


Collision coverage pays for damages to your vehicle when you are involved in a car accident or hit an inanimate object, like a tree. Your insurance company should cover your losses even if you are the at-fault driver.

Medical payments

Medical payments (Medpay) coverage pays for your healthcare services even if you are the at-fault driver in a car accident. Your insurer may cover ambulance fees and health insurance deductibles and copays. Healthcare services, including surgeries, x-rays and nursing services are also covered under Medpay coverage. If you're not at fault, the other driver's liability insurance will cover some or all costs.

In no-fault states, this insurance coverage is typically called no fault coverage or personal injury protection (PIP). PIP pays for lost income if someone is too injured to return to work.

Filing a Claim After an Accident

Whether someone hits your car or if you're at fault, you should pull over to safety and call a police officer. If there are any injuries after a car accident, call an ambulance. Next, take pictures and videos of the accident scene and collect the information of all the drivers involved as well as witnesses.

Remember to stay calm and do not immediately admit fault. Do your best to avoid physical contact and verbal altercations with the other party.

As soon as it is safe to do so, you should call your insurance company to start a car insurance claim — even if you believe the other driver is at fault. Your insurance adjuster will instruct you on next steps and walk you through the claims process. They may request documentation to support your case, such as photos, videos and a copy of the police report.

Remember: the other driver's insurance company will likely be investigating the car accident case as well. Generally, it should take two to three weeks or longer for insurance companies to determine fault.

Side impacts typically occur at intersections and determining fault depends on who had the right of way.


Will being at-fault affect my insurance premiums?

Being at-fault for a car accident may raise your insurance premiums, especially if you have a claims history full of accidents. If you have accident forgiveness on your policy, your insurer may not increase your rates after your first accident.

What is a 50/50 car accident claim?

A 50/50 car accident claim occurs when both drivers share equal responsibility for causing the accident. Therefore, each driver will pay 50% of the other driver's losses. If both drivers suffered $1,000 in damages, each driver would pay $500 toward the other driver's expenses.

Do adjusters determine fault?

When determining fault in a car accident, the adjuster will consider the type of accident and whether the driver violated traffic laws. Rear-ends, driving while distracted and speeding, for example, signal negligence. Adjusters may review traffic cameras and contact eyewitnesses to more accurately determine fault.

How long does it take for insurance companies to determine fault?

It will typically take two to three weeks or longer for a car insurance company to determine which driver is at fault for causing the accident.

Who is at fault if you get hit from the side?

Side impacts typically occur at intersections and determining fault depends on who had the right of way. The driver who ran a red light or stop sign before T-boning another driver would likely be labeled as the at-fault driver.

Protect Yourself in Case of Accidents

Accidents can be scary and happen when you least expect them. While you're recovering from the shock and dealing with the aftermath, the last thing you want to worry about is the price tag for the resulting damages.

Having the right car insurance can help pay for vehicle damage repairs, defense fees and more. If you're buying auto insurance for the first time or changing providers, SmartFinancial can help you find the best protection at the lowest prices. We analyze quotes and coverages from insurance companies in your area to match you with the right policy. Enter your zip code below to receive your free quotes.

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