Electronic logging device

What is an electronic logging device?

An ELD is hardware connected to a commercial vehicle's engine that automatically records driving time. It captures when the engine is running and when the vehicle is in motion.

It replaced handwritten paper logs, which were easy to falsify and were sometimes known within the industry by informal names reflecting that.

The federal mandate requiring them was a significant change for injury cases, converting a swearing contest into a documentary record.

For injury cases the mandate changed what is provable. Fatigue arguments that once rested on inference now rest on recorded data.

What data does an ELD capture?

The record is more detailed than a simple hours total.

• Engine on and off times
• Vehicle movement and duration of driving periods
• Miles driven during each period
• Duty status changes entered by the driver
• Location information at intervals
• Edits and annotations made to the record

Why does the edit history matter?

Because drivers and carriers can annotate entries, and the system records those changes. A record showing driving time reclassified as off duty raises obvious questions.

Unassigned driving time is similarly revealing. Miles logged without an assigned driver suggest either a records problem or an attempt to obscure who was operating.

This is why obtaining the underlying data rather than a summary report matters. A printed summary can look clean while the audit trail tells a different story.

Comparing ELD entries against fuel, toll and delivery records is standard practice, since inconsistencies across independent sources are difficult to explain.

How quickly must ELD data be preserved?

Immediately. Retention periods for these records are limited by regulation, and data can be lost through routine practices well before a lawsuit is filed.

A spoliation letter should therefore go out as soon as a serious truck crash is identified, specifying the ELD data along with related records.

Where preserved data is later found missing after such notice, courts may permit an inference that it would have been unfavorable to the carrier.

Related telematics systems may hold additional data on speed, braking and location, so preservation demands should reach those as well.

Common questions

Can ELD data be altered?

Entries can be edited, but the system retains an audit trail of changes. That trail is often as valuable as the underlying record.

Do all trucks have ELDs?

The mandate applies broadly to commercial drivers required to keep records of duty status, with limited exemptions for certain operations and older vehicles.

How do I get the data?

Through a preservation demand followed by a request for production in litigation. Acting quickly matters because retention windows are short.

What if the driver was exempt from using an ELD?

Some operations fall outside the mandate, in which case paper records or other documentation apply. Even then, fuel receipts, toll data, delivery timestamps and dispatch messages build an independent timeline, which is frequently more persuasive than any log because it comes from multiple unconnected sources. Discrepancies across them are difficult to explain.