Black Box and ELD Evidence in Truck Accident Claims

What a Truck Actually Records

People picture an aircraft flight recorder. The reality is several separate systems, each recording something different, each with its own retention behavior, and each held by the carrier rather than by any neutral party.

What This Evidence Actually Proves

The value is that it replaces argument with measurement:

• Whether the driver braked at all. The absence of braking before impact is one of the most telling facts available, and it points toward fatigue, distraction, or a medical event rather than a failed avoidance attempt.
• Actual speed, against the posted limit and against what was safe for the conditions.
• Following distance, where collision-mitigation systems logged warnings.
• Hours behind the wheel, against federal limits.
• Steering input, which distinguishes a gradual drift from a deliberate maneuver.
• Prior behavior — many systems log warnings and interventions over weeks or months, which can establish a pattern the carrier knew about.
• Route and stop history, which can contradict a logbook showing off-duty time.

Cross-referencing matters as much as any single record. Fuel receipts, toll transactions, and dock check-in times are third-party timestamps that can contradict a driver’s log, and a discrepancy between them is itself powerful evidence.

Published By

Shiner Law Group, P.A.

Founded by David I. Shiner, Esq. · AV Preeminent® rated · Florida Bar member since 2002

Shiner Law Group was founded by David I. Shiner, Esq., a Nova Southeastern University law graduate, a member of The Florida Bar since 2002, and AV Preeminent® rated by Martindale-Hubbell. The firm represents injured people across Florida from offices in Boca Raton, West Palm Beach, Fort Lauderdale, Fort Pierce, Orlando, Wellington, and Belle Glade, and handles truck accident cases on contingency: free consultations, and no fee unless there is a recovery.

The firm works to keep this information current and consistent. Spotted something wrong? Email joseph@shinerlawgroup.com and we will fix it. About this site →

Preservation, and Why Timing Decides It

Here is the difficulty. None of this evidence belongs to you, none of it is held neutrally, and a carrier is generally entitled to run its ordinary retention policies — including deletion — until it is on notice that the material matters to a claim.

A spoliation letter provides that notice. It is a formal written demand that the carrier preserve identified categories of evidence: the vehicle itself, ECM and EDR data, ELD records, telematics, camera footage, maintenance and inspection files, the driver qualification file, and dispatch records. Once it is received, routine deletion stops being routine.

Timing is everything. Sent within days, it preserves footage that would otherwise cycle out. Sent after a month, it may arrive to find the most probative material already overwritten, entirely lawfully. This is the single strongest practical reason to get advice quickly after a serious truck crash, even before deciding whether to bring a claim at all.

Where evidence is destroyed after notice, courts have remedies — which is why the letter has force. But a remedy for lost evidence is never as good as the evidence itself.

Timing also interacts with Florida’s filing deadline. Negligence claims arising after March 24, 2023 must generally be brought within two years, and claims involving a government entity carry far shorter pre-suit notice requirements under Fla. Stat. § 768.28. Neither deadline pauses while evidence is being gathered, which is why the preservation demand and the assessment of who may be responsible normally happen at the same time rather than in sequence. See Florida’s Truck Accident Deadline.

How the Data Is Actually Obtained

1. Preservation demand sent to the carrier and its insurer identifying every category of evidence.
2. Inspection request for the vehicle before it is repaired or returned to service, usually with an engineer present to supervise the download.
3. Formal discovery once suit is filed, compelling production of records a carrier will not provide voluntarily.
4. Third-party requests to municipalities and nearby businesses for intersection and surveillance footage, which have their own short retention windows.
5. Expert analysis to interpret the downloads, since raw ECM output is not self-explanatory and different manufacturers record differently.

Downloads are normally performed by a qualified technician using manufacturer-specific tools. Attempting to access the data informally risks corrupting it, and a download performed without proper protocol can be challenged later.

What to Do to Protect This Evidence

1. Record the DOT number and trailer number at the scene.
2. Note camera housings on the tractor mirrors and cab, and any nearby business or traffic cameras.
3. Do not authorize repair or release of your own vehicle until it has been examined, since it carries its own event data.
4. Get legal advice within days, not weeks, so a preservation demand goes out while the material still exists.
5. Do not give a recorded statement to the trucking company’s insurer before speaking with an attorney.
6. Keep your own records — photographs, the crash report number, and witness details.

See What to Do After a Truck Accident for the full sequence.

Black Box and ELD Evidence FAQ