Who Is at Fault in an Arizona Rear-End Collision

Attorney Answer

In an ordinary rear-end collision the driver who failed to stop is the one at fault — and Arizona does not take away your claim just because you may share some of the blame.

Arizona has a specific rule for this. Under A.R.S. § 28-730(A), a driver "shall not follow another vehicle more closely than is reasonable and prudent," having due regard for the speed of the vehicles, the traffic, and the condition of the highway. A violation can support a finding of negligence in a rear-end collision. That is why the following driver starts on the back foot: they are expected to leave enough room to stop for whatever the car in front does, including stopping suddenly in traffic.

It is not automatic, though. The front driver's conduct can matter — an unlit vehicle, a reversing car, a deliberate brake-check, a sudden lane change into a gap that was too small. That is where Arizona's fault rule comes in. Under A.R.S. § 12-2505(A), Arizona uses comparative fault: a claimant's own negligence reduces the damages recoverable in proportion to the claimant's relative degree of fault, but it does not bar recovery. The statute contains one express exception — there is no right to comparative negligence in favour of a claimant who has intentionally, wilfully, or wantonly caused or contributed to the injury or wrongful death. Ordinary inattention is negligence at most, so it reduces what you recover rather than defeating your claim.

That cuts both ways, and it is worth saying plainly. If you were the following driver, A.R.S. § 12-2505(A) means you are not automatically shut out from recovering for your own injuries either. Your share of fault reduces your recovery; it does not erase it.

What you can do

1. Get the traffic collision report and check the diagram, the narrative, and whether either driver was cited. A citation for following too closely is direct evidence of an A.R.S. § 28-730(A) violation. 2. Photograph both vehicles' damage and the roadway. The location and depth of damage is what an engineer uses to reconstruct the impact. 3. Write down whether traffic ahead was stopped, slowing, or moving, and whether the front vehicle's brake lights were working. 4. Look for cameras — dashcams, business security cameras, doorbell cameras. Request preservation in writing quickly, since most systems overwrite within days. 5. Get medically evaluated now and keep every appointment. Treatment gaps are the most common argument used to discount an injury claim. 6. Do not give the other driver's insurer a recorded statement before you have advice. 7. Confirm the Arizona filing deadline for your claim with a lawyer promptly.

⏱ Time limits apply. Arizona sets a filing deadline for injury claims, and it is shortened substantially if a government vehicle, a city bus, or a government employee was involved, because a written notice of claim must be served on the public entity long before any suit is filed. Confirm which applies to your facts with an Arizona lawyer before assuming you have years to decide.