When a commercial truck hits a car, two investigations start. One is yours. The other belongs to the trucking company and its insurer, and they often start theirs before you've left the hospital.
Trucking companies know what's at stake in a serious crash. Many have people who respond quickly after a wreck, talk to the driver, and start shaping the company's version of events. Their goal is simple: control the story before anyone else can tell it.
I've spent years litigating truck cases, examining the data these trucks generate, and using it in depositions. Here's how the evidence actually gets built, how I use it to pin down what happened, and why the first few weeks matter so much.
Step One: The Preservation Letter
The first thing I send in a truck case is a preservation letter. It puts the trucking company on formal notice that litigation is coming. It also tells them to preserve specific evidence: the truck's electronic data, driver logs, dashcam footage, dispatch records, maintenance files, and the driver's employment file.
This matters because much of that evidence disappears on its own. Federal rules only require carriers to keep driver logs and supporting documents for six months. Electronic data on the truck can be overwritten once it goes back on the road. Dashcam systems often record over old footage. None of that requires bad intent. It's just routine, and routine destruction is exactly what a preservation letter is designed to stop.
Once a company is on notice and destroys evidence anyway, Colorado courts can respond. In Aloi v. Union Pacific Railroad (2006), the railroad destroyed inspection and maintenance records under its routine retention policy, even after it knew a lawsuit was coming. The trial court told the jury it could infer the missing records would have hurt the railroad. The Colorado Supreme Court upheld that instruction. A trucking company that "loses" its logs after receiving my letter faces the same risk.
The Evidence, and What Each Piece Tells You
The engine control module (ECM). Often called the black box, it can record speed, braking, throttle, and cruise control in the moments around a crash. It tells you whether the driver was speeding, when he hit the brakes, and whether he braked at all.
Electronic logging device (ELD) records. These track the driver's hours. Federal rules generally limit a property-carrying driver to 11 hours of driving after 10 consecutive hours off duty. He can't drive past the 14th hour after coming on duty, and he must take a 30-minute break after 8 hours of driving. In one case, the logs showed a driver who appeared to have been running past his legal hours. You only find that if you get the records before they're gone.
Dashcam footage. Many fleets now run forward-facing cameras, and some also record the driver. Footage can show following distance, lane position, and whether the driver was looking at the road or at a phone.
GPS, telematics, and dispatch messages. These show where the truck was, how fast it was moving over time, and what the company was telling the driver. Dispatch messages can reveal whether the driver was being pushed to make a delivery window.
The driver qualification file. Every carrier must keep a file on each driver, covering his license, medical certification, driving record, and employment history. It can show a driver who never should have been behind the wheel.
Maintenance and inspection records. Brakes, tires, and lights all have to be inspected and maintained. A truck that was overdue for brake work tells its own story.
Post-crash drug and alcohol testing. Federal rules require carriers to test the driver after crashes involving a death. They also require testing after crashes where someone needs medical treatment away from the scene, or a vehicle has to be towed, if the driver gets a citation. Alcohol tests are supposed to happen within two hours and can't be done after eight. Drug tests must be done within 32 hours. If the carrier didn't test when it was required to, that's worth knowing.
Not Every Case Needs Every Download
Here's something most law firm websites won't tell you: I don't order every expensive download on every case.
A preservation letter goes out on essentially every truck case, because it costs nothing and protects everything. But a professional ECM download, an accident reconstruction expert, and a forensic review of months of logs can cost thousands of dollars. On a serious injury case where liability is disputed, that's money well spent. On a smaller case where fault isn't in question, it can eat into your recovery without changing the result.
How I decide: case by case, based on what the evidence could actually prove and whether it's worth the cost to you. The preservation letter keeps the option open while we figure that out.
The same thinking applies to proving the damages side of a serious case. I walk through how catastrophic truck claims get valued, and when experts like life care planners are worth the cost, in What Is a Catastrophic Truck Injury Claim Actually Worth in Colorado?
How It All Fits Together
No single piece of data tells the whole story. The real value comes from lining it all up into one timeline: when the driver came on duty, how long he'd been driving, how fast he was going, when he braked, what the camera shows, and what dispatch was telling him.
When all those sources agree, you have a clear picture of what happened. When they don't, that's usually where the case is. A driver who says he was going 55 when the ECM says 68, or who logged a break the GPS says never happened, has a credibility problem the jury will notice.
How I Use It in Depositions
The evidence is only as good as what you do with it. My approach to deposing a truck driver is deliberate.
I start general. I don't show him the logs, the footage, or the ECM data. I ask about his schedule that day, his training, his breaks, how fast he was going, and what he saw. I let him tell his story in his own words, for as long as it takes.
Then, toward the end, I bring in the evidence. I walk through it piece by piece and confront every place where his account doesn't match the data. By then he's committed to his version, and he can't easily walk it back.
I generally depose the company itself later, through a designated corporate representative. The order matters. Taking the driver first means his story isn't shaped by the company's official position. Then, in the company deposition, I can walk through the company's own safety policies and every one the driver broke. The company has to either defend his conduct or admit it violated its own rules.
For more on what makes crashes on Colorado's mountain corridor different, see my post on I-70 truck crashes.
What Trucking Companies Argue
"It was the weather." Colorado law requires every driver to drive for the conditions, and the Colorado Supreme Court has rejected the idea that ice or snow excuses a driver who wasn't driving carefully enough. See my post on Colorado's Traction Law for more.
"It was your fault." Expect the insurer to look for any share of blame it can put on you. Under Colorado's comparative fault rule, your share reduces your recovery, and 50% or more bars it entirely. The data often ends this argument.
"The driver was an independent contractor." Trucking companies sometimes try to distance themselves from the driver. That's rarely the end of the analysis. Responsibility often depends on the lease agreements and contracts, which is one more reason to request them early.
If you've been hurt in a crash with a commercial truck, learn more about how I handle truck accident cases.
What It Costs to Hire Me
My fee is 29% pre-litigation and 33% if we sue, compared to the 33-35% and 40-45% most Colorado firms charge. On a $100,000 recovery in litigation, the difference between 33% and 40% is $7,000 that stays with you. See the full breakdown on my fees page, or call 877-2929-LAW.
Trucking Evidence FAQ
How long does a trucking company have to keep the driver's logs?
Federal rules require carriers to keep records of duty status and supporting documents for six months. That's why a preservation letter should go out as early as possible.
Does every truck crash case need a black box download?
No. A preservation letter protects the data, but whether a professional download is worth the cost depends on the case, especially whether liability is disputed and how serious the injuries are.
What happens if the trucking company destroys evidence?
If a company destroys relevant evidence after it knew a lawsuit was likely, Colorado courts can instruct the jury that it may infer the evidence would have been unfavorable to the company.
Will the truck driver be drug tested after the crash?
Federal rules require testing after crashes involving a death. They also require it when someone needs medical treatment away from the scene, or a vehicle has to be towed, and the driver gets a citation. Alcohol tests must happen within eight hours, and drug tests within 32 hours.
Why depose the driver before the company?
So the driver's account isn't shaped by the company's official position. Then the company can be confronted with its own policies and the ways the driver broke them.
This post is general information, not legal advice. Every case is different.
