Truck Accident vs. Car Accident in Arizona: Why the Claims Are Different

Why Federal Law Governs Commercial Truck Crashes

Commercial truck crashes are not just governed by Arizona traffic law; they fall under a separate layer of federal regulation administered by the Federal Motor Carrier Safety Administration (FMCSA), codified at 49 CFR Parts 390 through 399. That parallel framework changes what you can claim and who you can hold responsible.

FMCSA rules cover how long a driver can be on the road without rest (hours of service rules, 49 CFR Part 395), how a truck must be inspected and maintained, how cargo must be loaded and secured, and what safety equipment the vehicle must carry. Every violation of those rules is potential evidence of negligence that goes beyond what a typical car crash case involves. In a car accident, you are generally asking whether a driver exercised reasonable care on the road. In a truck case, you are also asking whether the carrier trained the driver properly, whether the company enforced the rest rules, whether the truck was roadworthy when it left the terminal, and whether the cargo was loaded correctly. Those are separate duties, and separate parties can bear them.

Maricopa County accounts for approximately 40 percent of all commercial vehicle crashes in Arizona (ADOT), and I-10 logged 847 crashes in 2024 (ADOT). I-10 is a primary east-west freight corridor that runs through the Phoenix metro area; the volume of commercial traffic on it is among the highest in the state. When those vehicles are involved in crashes, the legal landscape is fundamentally different from a two-car collision on a local street.

Who Can Be Held Liable Beyond the Truck Driver

In a car accident, liability typically resolves to one or two drivers. In a commercial truck case, the defendant list can include the truck driver, the motor carrier that owns or leases the truck, the shipper that loaded the cargo (if improper loading contributed to the crash), the trailer owner if different from the motor carrier, and any maintenance contractor that performed negligent inspections or repairs. Each of those parties may carry separate insurance policies, and each may dispute responsibility by pointing at the others.

The motor carrier is a particularly important defendant. Under federal law and Arizona tort principles, carriers are responsible for the conduct of employed drivers, and they have independent duties regarding driver qualification, training, drug and alcohol testing, and vehicle maintenance. A carrier that hired a driver with a history of hours-of-service violations or failed to properly inspect brakes has its own liability exposure, separate from what the driver did behind the wheel at the moment of impact.

A fully loaded 18-wheeler can weigh up to 80,000 pounds, compared with roughly 4,000 pounds for an average passenger car. At highway speed, that mass differential produces catastrophic injury. The legal complexity of identifying all responsible parties is proportionate to the severity of what those crashes produce.

The Evidence in a Truck Case That Does Not Exist in a Car Case

Commercial trucks carry data-recording systems that passenger vehicles typically do not. The engine control module (ECM) and event data recorder (EDR), often called the black box, capture speed, braking force, throttle position, acceleration, and in some systems, GPS location in the seconds before and during a crash. That data is often the most objective evidence of what the truck was doing when the collision occurred.

The problem is that trucking companies know the data exists. Carriers have standard recording cycle schedules, and data can be overwritten or lost if the ECM is not specifically preserved. Some carriers have rapid response teams, consisting of lawyers and adjusters, that arrive at crash scenes quickly to assess liability, secure their own evidence, and begin shaping the factual record before the injured party has retained counsel. That is not illegal; it is standard practice. But it means the injured party who waits weeks or months to consult an attorney may find the most valuable evidence is gone.

Driver logs and electronic logging device (ELD) records under 49 CFR Part 395 are a second category of truck-specific evidence. Hours-of-service violations, which show a driver was beyond the legal driving time limit, are some of the strongest indicators of carrier negligence. Carriers are required to retain these records for a set period, but that retention window has limits. A spoliation letter, sent by your attorney demanding preservation of all data, is one of the first actions that needs to happen after a truck crash, often before any formal legal proceeding begins.

Physical inspection records, maintenance logs, driver qualification files, and training records are all discoverable in litigation and may not be preserved indefinitely by a carrier that sees them as a liability.

Why You Need to Act Faster in a Truck Accident Than in a Car Crash

Arizona’s statute of limitations for personal injury claims is two years under A.R.S. § 12-542, the same deadline that applies to car accident cases. The deadline is identical; the evidence half-life is not. In a car accident, the most important evidence is typically the police report, photos, and the vehicles themselves. Those things persist. In a truck case, the black box data may be overwritten in days or weeks, the driver’s logs have a regulatory retention ceiling, the carrier’s internal communications about the crash are not preserved automatically, and the rapid response team the carrier sends to the scene is building a litigation file from day one.

The two-year clock does not mean you have two years to start gathering evidence. It means you have two years to file a lawsuit. The evidence window is far shorter. An attorney who receives a truck accident case six months after the crash is working with a materially weaker evidentiary record than one retained within the first few weeks.

Beyond evidence, acting early matters because the carrier’s insurer will likely contact you. Trucking companies carry significant commercial insurance policies; their adjusters are experienced at resolving claims quickly, and a quick resolution almost always favors the carrier, not the injured person. Accepting an early settlement offer closes your claim permanently, including for injuries that have not yet fully manifested or future medical costs that have not yet been incurred.

Arizona’s comparative fault statute (A.R.S. § 12-2505) means your recovery is reduced by your percentage of fault. A carrier with professional claim-handlers on the scene from the beginning has a head start on building that fault argument. You need someone in your corner just as fast.