Chicago Truck Accident ELD Preservation Attorney

The crash happens. The carrier's risk management team is on the phone with defense counsel before the first responder finishes the report. They know the clock.

Seventy-two hours after a serious crash, most commercial carriers have retained a third-party crash reconstruction vendor, pulled the ECM download at the truck, and decided which pieces of electronic evidence they intend to rely on at trial. The data that supports their theory is preserved. The data that does not can be allowed to cycle off.

The plaintiff's side has no such pipeline running on day one. That is the asymmetry. Closing it requires one document in the carrier's hands within 48 hours of the crash.

Three systems matter. The ELD records duty status — on-duty driving, on-duty not driving, sleeper berth, off-duty — in 15-minute increments. Modern interstate trucks are required to use one under 49 CFR § 395.8. The ECM (engine control module) records hard-brake events, speed, RPM, throttle position, and fault codes — the core evidence in defective-brake cases. Third-party telematics — Omnitracs, Samsara, Lytx, PeopleNet — record GPS position, g-force events, and frequently dashcam video.

The retention windows vary. ELD: six months by rule, though the device itself rolls at eight days. ECM: depends on the engine manufacturer — Detroit Diesel and Cummins typically hold last-stop data plus a two-minute snapshot around hard events. Telematics: carrier-specific, but dashcam footage is commonly retained 30 to 90 days unless an incident flag is set.

A spoliation letter must specify all three. Naming only "ELD records" gives the carrier room to argue that ECM data was not included in the hold.

The letter is not complicated. It names the crash, the carrier, the truck unit number, and the categories of data to be preserved — ELD records, ECM downloads, GPS telematics, dashcam footage, dispatch records, bills of lading, fuel receipts, maintenance logs, pre-trip and post-trip inspection reports, driver qualification file, drug and alcohol testing records, and any third-party crash-reconstruction material the carrier generates.

What the letter does is shift the legal landscape. Once the carrier is on notice of litigation, the duty to preserve attaches. Subsequent destruction of the evidence — even routine cycling — is spoliation. Illinois courts apply a rebuttable presumption of adverse inference when spoliation is established, which means the jury is instructed to assume the missing evidence would have been unfavorable to the party that lost it.

We send the letter by certified mail, email, and fax within 48 hours of being retained. Every step is timestamped. The proof of service becomes part of the case file and, if spoliation is later proved, the foundation for the adverse-inference instruction.