San Antonio is a major city located in Texas, United States. In San Antonio, more than 300 crashes a year involve commercial trucks, and many of these accidents turn into legal battles. Trucking companies act quickly to safeguard their drivers. However, the most crucial evidence, the truck’s black box, may already be recording new data or could be sitting in a mechanic’s bay.
That black box holds second-by-second proof of what the truck was doing: how fast it was going, whether the driver hit the brakes, and whether they were following the rules of the road. Without that data, you rely on guesswork in a system built on evidence.
Black box data is one of the first things a truck accident lawyer in San Antonio will want to get their hands on. Because when you’ve been hit and everything’s a mess, this little black box might be the key to proving the truth.
What is Black Box Data?
Most commercial trucks today come equipped with an event data recorder (EDR), commonly called the black box. It works a lot like the one on airplanes. The data it collects isn’t limited to just speed or braking. It also captures an entire stream of actions, including throttle percentage, brake use, gear changes, sudden acceleration or deceleration, and steering inputs.
It also records whether the driver activated the turn signal, if the anti-lock braking system kicked in, and even the RPM of the engine in the moments leading up to the crash. That means it doesn’t just show how fast the truck was going. It goes further to tell whether the driver floored the gas pedal or hit the brakes hard. It reveals how much time has passed between the driver reacting (or not reacting) and the crash.
If the driver swerved, if the truck veered, or if it didn’t slow down at all, that data is there. All of these details are gold nuggets because, after a crash, there’s usually confusion, finger-pointing, and a lot of pressure to find out who was really at fault. The black box doesn’t rely on memory. It simply gives you what actually happened.
What Black Box Data Does
Here are some reasons why data from the black box is so extensively valued:
Prove fault
Things are usually complicated in a truck accident, especially those involving injuries or fatalities. Trucking companies usually have legal teams and insurers on standby, ready to protect themselves the moment something goes wrong. If you’re the one who got hit, you’re at a disadvantage unless you act quickly and get your hands on the data.
In Texas, comparative fault laws mean your compensation can be reduced if you’re found partially at fault. But with solid black box data on your side, you’re not stuck relying on assumptions or hearsay. Instead, you’re presenting proof.
Show the driver’s behavior before the crash.
One of the most important things this data shows is whether the driver actually reacted or failed to. If the data shows no braking until a fraction of a second before the crash, that suggests distraction or fatigue. It also captures turn signals, steering wheel movement, and sharp corrections.
That matters when you’re trying to figure out if a lane change was deliberate or accidental. Perhaps the debris caused the driver to jerk the wheel, or they attempted to avoid colliding with someone. It builds a clear picture of decision-making in those final moments, something no witness can fully describe.
Spots rule violations and hours-of-service issues
Truck drivers are held to strict federal and state regulations, especially when it comes to how long they can drive without resting. In Texas and across the U.S., hours-of-service laws exist to keep exhausted drivers off the road. But those rules only work if drivers actually follow them.
Black box data, especially when combined with the truck’s electronic logging device (ELD), can expose any violations. It can show whether the truck had been moving non-stop for too long or if the driver skipped mandatory rest breaks.
If a crash happens near the end of a long drive, and the driver was pushing past their legal limit, that could explain delayed reactions, poor judgment, or falling asleep at the wheel.