After health and safety issues for everyone involved in a vehicle collision have been determined, the number one question is “Whose fault was it?”

The answer is essential for more than just the parties’ vindication. Insurance companies and the authorities have to know who’s responsible so they can decide on payments and penalties. Fault determines who pays for auto repairs and medical bills.

How do they come to a conclusion? During the incident, events can happen so fast that nobody remembers whose fault it might have been. Here’s what you should know about that determination.

Guidelines Based on Fault vs. No-Fault States

The outcome of the at-fault report depends on whether you live in a no-fault or tort (at-fault) state. If a collision occurs in a tort state, blame falls on the person who appears to have caused the accident, and the driver’s insurance is required to pay for repairs, medical expenses, and perhaps other costs such as lost wages or pain and suffering. 

In a no-fault state, each driver is responsible for his or her own medical bills after the incident, up to a threshold. The at-fault party still has to pay for any damages to your property, but no-fault law typically makes no allowances for medical coverage.

Many people who live in a no-fault state carry personal injury protection or personal medical coverage so they’re covered in a crash. 

Witness Accounts 

In most states, the first two or three vehicles who happen upon a collision are required by law to stop until any injured parties have been cared for, and they’ve provided a witness statement to authorities. Gathering as many witness statements as possible is key, because each person will have seen the accident from a different angle.

Authorities piece together all the statements to clarify who was in the wrong and how the incident occurred. 


Witness statements are useful, but they don’t necessarily tell the whole story. Likewise, not all crashes have a witness. When authorities are left with no or questionable visual accounts, they’ll turn to forensics.

They’ll start by taking pictures of and examining the roadway. Skid marks, broken glass, contact angles, and other clues can offer hints about who made contact first. Using principles of physics, investigators may be able to map out what happened and why the collision occurred. 

Many officials will go through a car accident reconstruction process, during which they gather all the possible evidence to determine fault. This is most common in a personal injury case, which requires a level of certainty beyond reasonable doubt that a particular party was at fault.

Authorities will examine operational capability of the vehicle systems (tire tread, brakes, steering, and suspension). They’ll consider friction values for the surface, angle of the steering wheel, throttle position, force of impact, seatbelt status, and so on.

Each of these micro details can come together into a clear outline of what happened at the accident and who’s at fault.

Collect Evidence and Avoid Admitting Fault 

You can do your part to help the authorities by gathering as much evidence as possible at the scene. First, don’t say anything that might incriminate you.

This isn’t about trying to get away with something you’re guilty of; you don’t know the whole story. The other driver might have been at fault as well, and if you readily accept the blame, you could potentially shift the entire financial burden onto your shoulders, even if you were only partially at fault.

If you have the health and presence of mind, take pictures and information at the scene. Gather phone numbers of witnesses for future consultation if need be. This evidence can be invaluable for protecting your interests, especially if you’re served with a personal injury suit later on.

Things happen very quickly in a vehicle collision, so it’s comforting to be able to hand the at-fault determination to the professionals. It can be a lengthy process, but they’ll factor in many considerations before determining who was at fault.