T-Bone and Red-Light Accidents in Phoenix: Proving Who Had the Signal

Two drivers, one intersection, and both absolutely certain they had the green. An intersection accident in Phoenix almost always comes down to a swearing contest over signal timing — until the evidence settles it. Here’s what Arizona law actually requires at a signal, and the proof that decides who’s telling the truth.

What the signal actually requires, color by color

Arizona Revised Statutes § 28-645 requires a driver facing a steady red signal to stop before entering the intersection and stay stopped until the light changes. Turning right on red is allowed only after a complete stop, and only where not otherwise posted. A driver facing yellow is warned that the signal is about to turn red and generally shouldn’t enter the intersection if they can stop safely. The statute focuses on where a vehicle was when the light changed, not simply what color it was at some point during the approach.

Why “I had the green” isn’t the end of the analysis

Even a driver with a green light must yield to vehicles and pedestrians already lawfully in the intersection. That matters most in left-turn crashes. A driver turning left on a plain green circle doesn’t have the right-of-way over oncoming traffic. They must yield to any vehicle close enough to be an immediate hazard. A large share of intersection crashes happen exactly here — a left-turning driver misjudging oncoming speed, not a blown red light at all.

The evidence that actually settles a “who had the light” dispute

• Red-light camera footage, where the intersection has one — request it immediately, since retention periods are often short
• Nearby business or doorbell camera footage facing the intersection
• The police report’s documentation of skid marks, point of impact, and vehicle resting positions, which often show the crossing driver’s path
• Witness accounts gathered at the scene, before drivers have compared notes on what they remember
• Any dashcam footage from either vehicle or a following car

Signal malfunctions change the analysis entirely

If a signal was inoperative or malfunctioning at the time of the crash, Arizona law treats the intersection like an all-way stop. Every driver must come to a complete stop and proceed only when it’s safe. A malfunction report to the city, combined with maintenance records, can become central evidence if a signal wasn’t working as it should have been.

Comparative fault at intersections

These crashes often involve conflicting accounts and few independent witnesses. Insurers frequently try to split fault under Arizona’s comparative negligence rule even where one driver’s fault is clearly greater. Physical evidence — not just testimony — is usually what shifts an adjuster off an even split.

The bottom line

An intersection accident in Phoenix rarely gets solved by two conflicting accounts of who had the light. Camera footage, the police report’s physical evidence, and prompt witness statements are what actually settle these claims. A driver’s green light doesn’t excuse a failure to yield to traffic or pedestrians already in the intersection.

Keep reading: Rear-end collision fault in Arizona · Comparative negligence in Arizona · or browse all guides from Awesome Attorneys.

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This article is general information, not legal advice, and reading it does not create an attorney–client relationship. Fault at an intersection depends on the specific evidence available in your case — review it with a licensed Arizona attorney before accepting any offer.