Here's something the trucking industry doesn't advertise: the pressure to keep a truck moving often outweighs the rules meant to keep a tired driver off the road. A fatigued truck driver isn't usually a bad person. They're often someone squeezed by a schedule that treats federal rest limits as a suggestion. When that pressure causes a crash, proving it takes more than a hunch, and the evidence has a short shelf life.
How Do You Prove a Truck Driver Was Too Tired to Drive?
You prove a fatigued truck driver caused a crash with data, not guesswork. Electronic logs, GPS records, and the driver's own duty history can show whether they broke federal limits on how long they were allowed to drive.
Fatigue leaves no skid marks. But it almost always leaves a digital trail, if someone knows where to look before it's overwritten.
What Are the Federal Hours-of-Service Limits?
Hours-of-service rules are federal limits on how long a commercial driver can be behind the wheel before they must rest. The Federal Motor Carrier Safety Administration (FMCSA) sets them, and they apply to most interstate truck drivers.
The core limits are worth knowing, because a crash often traces back to one of them being broken:
- A driver may drive up to 11 hours after 10 straight hours off duty.
- All driving must happen within a 14-hour on-duty window, which does not pause for breaks or loading.
- A 30-minute break is required after 8 hours of driving.
- Weekly caps limit a driver to 60 hours over 7 days or 70 hours over 8 days, resettable only with a 34-hour break.
When a carrier or driver ignores these, and someone gets hurt, that violation can become the center of a negligence claim.
What Is an ELD, and Why Does It Matter?
An ELD, or electronic logging device, is a federally required tool that automatically records a truck's driving time and duty status. Since late 2017, most commercial trucks must run one. Before ELDs, drivers kept paper logs that were easy to fake, so easy that the industry nicknamed them "comic books." The ELD made a driver's hours much harder to hide, which is exactly why they're so valuable after a crash.
How Fatigue Actually Gets Proven
Fatigue is proven by cross-checking multiple records that, together, show a driver was pushing past safe limits. No single document tells the whole story, so investigators layer them.
| Evidence Source | What It Reveals |
| ELD data | Actual driving hours, duty status, and whether limits were exceeded |
| GPS and telematics | Where the truck was, how fast, and how long it had been rolling |
| Dispatch and delivery records | Whether the schedule made legal rest impossible |
| Cell phone records | Activity that suggests the driver was awake and working, not resting |
| Fuel and toll receipts | A timeline that can contradict a falsified logbook |
The power is in the overlap. When a logbook says a driver was resting but toll data shows the truck moving, the logbook loses.
Can a Driver's Logs Be Falsified Even With an ELD?
Yes, though it's harder now. Some drivers log personal or off-duty time while still working, or carriers edit records after the fact. This is why independent sources like GPS, fuel receipts, and cell data matter. They provide a check the company can't quietly rewrite.
Why the Trucking Company Is Often the Real Target
Fatigue is frequently the symptom, not the disease. The disease is a schedule, and schedules are set by companies. That's why a fatigue claim often reaches past the driver to the carrier.
When a company builds routes that can't be run legally, pays only by the mile so drivers skip rest to earn a living, or ignores hours violations it can plainly see in its own data, the company has made a choice. Texas law can hold it responsible for that choice, both for its driver's conduct on the job and for its own decisions.
Does Pay-Per-Mile Encourage Fatigued Driving?
It can. When drivers earn only for miles driven, every hour resting is an hour unpaid. That structure quietly pushes drivers to stretch their hours, and courts can consider it when weighing a carrier's responsibility for a fatigue-related crash.
The Human Cost Behind the Rules
Fatigue impairs a driver in ways that resemble drunk driving: slower reactions, poor judgment, and microsleeps that last just long enough to miss a stopped car. Federal safety investigators have linked fatigue to roughly a third of fatal truck crashes.
That matters in Houston, where drivers share the Katy Freeway and the North Freeway with long-haul rigs running tight cross-country schedules. A driver 13 hours into a shift on I-10 has far less margin for the sudden brake lights of rush hour.
What Texas Law Says About Your Claim
Two Texas rules will shape a fatigue claim from the start: how fault is shared and how long you have to file. Both reward moving early.
Under Section 33.001 of the Texas Civil Practice and Remedies Code, Texas uses modified comparative negligence. If your share of fault tops 50%, you recover nothing; below that, your recovery drops by your percentage. Carriers often argue shared fault to shrink what they owe, which makes solid fatigue evidence essential.
The filing deadline is generally two years from the crash, under Section 16.003 of the Texas Civil Practice and Remedies Code. ELD and GPS data can be overwritten in weeks or months, so the legal clock and the evidence clock run at very different speeds.
Move Fast, Because the Data Won't Wait
The most important evidence in a fatigue case is also the most fragile. ELD records, GPS logs, and dispatch files can be overwritten on routine cycles unless a company is formally ordered to preserve them.
A Houston truck accident lawyer can send a preservation demand quickly, locking down the records before they cycle out. That data often works hand in hand with the truck's black box data, which captures the final seconds of driver input before impact.
Fatigued Driving Questions Answered by Attorneys
How is driver fatigue different from ordinary distracted driving?
Fatigue comes from too little rest and impairs reaction time and judgment across an entire shift, while distraction is a momentary lapse. Fatigue also ties directly to federal hours rules, which gives investigators a clear standard to test the driver against.
What if the truck driver was using paper logs instead of an ELD?
Some drivers qualify for short-haul exemptions and may use paper logs. Even then, GPS, fuel, and toll data can rebuild the real timeline and expose gaps between what was logged and what actually happened.
How quickly should evidence be requested after a fatigue crash?
As soon as possible, ideally within days. Electronic logs and telematics data are often retained only for a limited period before being overwritten, so a preservation demand early on can make or break the case.
Does a single hours violation prove the company was negligent?
It's strong evidence but not automatic. A pattern of violations, or a schedule that made compliance impossible, tends to carry more weight than an isolated overage. Investigators look at the whole operation, not just one shift.
How would I ever find out if the driver who hit me was over their hours?
You typically can't on your own, but a lawyer can compel the carrier to turn over ELD and dispatch records. Those show the driver's hours and whether federal limits were broken before the crash.
The crash report doesn't mention fatigue. Does that end it?
No. Officers at a scene rarely have access to a driver's logs or GPS history. Fatigue is often uncovered later, once the electronic records are pulled and cross-checked against the timeline.
Can I hold the company responsible, or only the driver?
Often both. If the carrier set an impossible schedule or ignored violations in its own data, Texas law can hold the company accountable alongside the driver.
The Clock That Caused Your Crash Leaves a Record
A tired driver behind 40,000 pounds is a preventable danger, and the systems that track their hours can prove when the rules were ignored. The Calderon Law Firm goes after those records fast, reads them closely, and follows the fatigue back to whoever put that driver on the road too long.
We've been there for more than 5,000 Texas families across Greater Houston and recovered over $200 million in settlements for our clients. A case review costs nothing, and in most injury cases we don't get paid unless you do.
If a drowsy trucker's schedule became your emergency on a Houston highway, call (346) 999-5673. Our bilingual team is on the line 24/7.