The Truck Crash Evidence Clock in Michigan: What a Carrier Must Keep, and What Disappears First

Short answer: After a serious truck crash in Michigan, the evidence that decides the case is mostly in the trucking company's hands, and federal rules only make the company keep it for a limited time. Hours-of-service records, including electronic logging device data, must be kept for six months; driver vehicle inspection reports for three months; maintenance records for one year; the driver's qualification file for the length of employment plus three years. Engine computer data, dashcam footage and nearby business video have no retention rule at all and may be overwritten much sooner. Michigan adopts these federal rules for in-state carriers too. A written preservation demand sent in the first days, before any of those clocks run, is the single most important step a family can take.

The injured person is usually still in the hospital when these clocks start, and nobody on the trucking company's side will mention them.

What records does a trucking company have to keep, and for how long?

A motor carrier regulated by the Federal Motor Carrier Safety Administration creates paperwork a private driver never does. The federal rules set a minimum retention period for each type. Michigan adopted the same federal motor carrier rules by statute, and for these purposes "interstate" in the federal text means intrastate or interstate under MCL 480.11a, so a carrier that never leaves Michigan generally keeps the same records. (The same section exempts public transit buses run by local agencies, which follow their own policies.)

Two things stand out. First, the shortest clocks belong to the records that matter most in a fatigue or defect case: the logs and the driver's own inspection reports. Second, these are minimums. A company may keep records longer, but nothing in the federal rules requires it to, and a company that follows its normal schedule can lawfully discard a log that would have shown the driver was past the 11-hour limit.

What evidence has no retention rule at all?

Some of the most useful data is not covered by any retention rule. It exists only until a system overwrites it or someone deletes it.

• Engine control module data. Many trucks record speed, braking and throttle in the moments around a hard stop or impact. That event data can be overwritten by later events, or lost when the truck is powered down, repaired or sold.
• Dashcams. Forward-facing and driver-facing cameras commonly record on a loop. Footage that was not saved may be recorded over.
• Telematics and dispatch messages. GPS location, speed history and messages between the driver and dispatch live on vendor systems with their own retention settings.
• The driver's phone. Call, text and app records sit with the phone carrier and the apps. Retention varies.
• Business and traffic video. Gas stations, warehouses and storefronts near the crash often keep video for a short time before the system records over it.

These windows vary by system and setting. Assume this data may be gone in days.

Was the truck driver tested for drugs and alcohol?

Not after every crash. Under 49 CFR 382.303, the carrier must test a surviving driver when the crash involved a death, or when the driver received a citation and someone was treated away from the scene or a vehicle had to be towed. When testing is required, the timing rules are strict. If the alcohol test is not done within two hours, the carrier must write down why, and it must stop trying after eight hours. The drug test must happen within 32 hours or attempts stop, again with a written explanation.

That written explanation is itself evidence. A missing test with a thin reason tells a jury something about how the company ran its safety program. Ask for the test result or the reason it was not done, by name, in the preservation letter.

How do you find out which trucking company is responsible?

Start with the truck itself. A carrier's name and USDOT number are usually marked on the side of the tractor, and the number often appears in the police report. That number unlocks the public record. The FMCSA's SAFER Company Snapshot can be searched by USDOT number, MC number or company name and gives a concise record of the company's identification, size, cargo and safety record, including any safety rating, a roadside out-of-service inspection summary and crash information.

The name on the door is not always the whole story. The truck may be leased to a carrier, the trailer may belong to someone else, and a freight broker may have arranged the load. On May 14, 2026, the United States Supreme Court held in Montgomery v. Caribe Transport II, LLC that a state-law claim against a broker for negligently hiring an unsafe carrier falls within the federal safety exception, so it is not preempted. The Court did not decide how that applies to a load that never left the state, so a Michigan-only haul is still an open question. Either way, the broker's carrier-vetting file and the broker-carrier contract belong on the preservation list.

Our guide to who pays after a catastrophic commercial vehicle crash in Michigan covers the insurance layers behind each of these companies.

What is a preservation letter, and what happens if the company ignores it?

A preservation letter (also called a spoliation letter) is a written demand that a company keep specific evidence because a claim is coming. It names the truck, the trailer, the driver, the date and the place, and it lists the records by type: logs and ELD data, engine data, dashcam video, telematics, dispatch messages, inspection and maintenance files, the driver qualification file, drug and alcohol testing records, the accident register, and any lease and broker documents. It goes to every company that may hold something, including the carrier's insurer.

Michigan law backs it up. In Brenner v. Kolk, 226 Mich App 149 (1997), the Court of Appeals held that a trial court has inherent power to sanction a party for failing to preserve evidence it knows or should know is relevant, even before a lawsuit is filed. One available sanction is an instruction that the jury may infer the missing evidence would have been unfavorable to the party that lost it. "May" matters: the jury is allowed to draw that inference, not required to. An inference is also a poor substitute for the actual video.

Two limits are worth knowing. Michigan does not recognize a separate lawsuit for destroying evidence; in Teel v. Meredith, 284 Mich App 660 (2009), the court treated spoliation as an evidence problem inside the main case, not as its own claim. And the duty runs both ways. Brenner itself involved an injured plaintiff who failed to keep the vehicle and its seat belt, and the court said sanctions could follow. A family should keep its own car unrepaired and unsold until it has been inspected, and should save photos, phone video and medical records.

Does the ticket decide who was at fault?

No. Whether the truck driver was cited, and for what, does not decide fault in the injury claim. The reconstruction, the logs, the engine data and the video are the case. That is exactly why the records above matter more than the police report, and why losing them can hurt more than losing a ticket.

What to do in the first week after a serious truck crash

1. Get the carrier's name and USDOT number from the police report, the side of the truck or photos taken at the scene.
2. Send written preservation demands to the carrier, any trailer owner and broker you can identify, and the carrier's insurer, listing every record type above.
3. Ask nearby businesses, in writing, to save any video of the crash.
4. Keep your own vehicle as it is. Do not let it be repaired, salvaged or sold before it is inspected.
5. Do not give a recorded statement to the trucking company's adjuster. That statement is for their file.
6. Give written notice of the injury to your own no-fault insurer so the one-year PIP clock is protected.

Michigan deadlines that run at the same time

The federal retention clocks are far shorter than either legal deadline. That gap is the trap: a family can have years to sue and still lose the proof in months. The Michigan injury deadline calculator shows the legal deadlines for a given crash date.

Common questions

Can the trucking company legally delete the driver's logs? Yes, after the six-month minimum, if no one has asked it to keep them and it does not reasonably expect a claim. Once a company knows or should know a claim is coming, Michigan courts can sanction it for losing relevant evidence. A preservation letter removes any doubt about what it knew.

Does every truck crash require a drug and alcohol test? No. Federal rules require it after a crash involving a death, or when the driver is cited and someone is treated away from the scene or a vehicle is towed. When a required test is late or missed, the carrier must record why.

Do these rules apply to a Michigan company that never crosses state lines? Generally yes. Michigan adopted the federal motor carrier safety rules and reads "interstate" in them to include intrastate operations. Transit buses run by public agencies are exempt from that statute.

Who sends the preservation letter? Anyone can send one, but it works best when it comes from a lawyer who knows which records to name and which companies to send it to. A vague letter invites a vague response.

Is the trucking company's insurer on our side? No. The adjuster works for the carrier and its insurer. Their early investigation is for their defense.

Talk to a Michigan truck accident lawyer

A free consultation can tell you which companies stand behind the truck, which records are at risk this week, whether a preservation demand has gone out, and which deadline is shortest. In a catastrophic case those answers shape everything that follows. Read more about our truck accident practice, why Michigan trucking cases are different, and our work on catastrophic injury cases.

Call (313) 800-0000 or request a free consultation. Koussan Law has offices in Detroit, Dearborn Heights and Marquette, and we work in English, Spanish and Arabic.