Northeast Freight Time one clock, four readings

What an ELD Actually Records

The electronic logging device mandate did something unusual: it made one category of working time machine-recorded and unfalsifiable, while leaving everything adjacent to it as before. For a software-oriented reference on recording work time, this overview page.

Understanding exactly where that line falls determines what an ELD can and cannot support in a detention claim, and the answer surprises people on both sides. For broader transportation and measurement context, see Associated Press.

Reviewed August 9, 2026. Sources: FMCSA and 49 CFR Part 395.

What it records automatically

An ELD connects to the engine control module through the diagnostic port and captures, without driver input: date, time, location, engine hours, vehicle miles, driver identification, and vehicle and carrier identity.

The behaviour that matters:

It switches to driving at 5 mph, automatically.

It registers stopped when speed is zero for at least three seconds.

After five minutes stationary in driving mode it prompts the driver, and if there is no response within sixty seconds it changes the status to on-duty not driving by itself.

And automatically recorded driving time cannot be edited to non-driving time. That is written into the technical specification, and it is the whole reason the mandate changed anything: the one status the machine determines is the one nobody can alter.

What it does not record

Detention. At all.

There is no detention status in an ELD. Time at a facility lands in on-duty not driving, which is a bucket containing loading, unloading, waiting, paperwork, fuelling, inspections and anything else that is work and not motion. The device cannot distinguish among them, and it was never asked to.

Off duty and sleeper berth are manually entered. So is the choice between on-duty not driving and off duty at a facility — a real decision with real consequences that the machine does not make.

So the asymmetry is: driving is measured, and everything else is declared. A driver's fourteen-hour clock is machine-verified at one end and self-reported at the other.

This is why FMCSA's 2023 study proposal asked whether existing intelligent transportation systems can measure detention at all. Nine years after the mandate, the agency was still asking whether the technology on every truck could answer the question. It largely cannot.

What an ELD does support in a claim

It is still useful evidence, within limits.

Arrival and departure by location and time. GPS-stamped, engine-derived, hard to dispute.

That the vehicle was stationary at that location for a given duration. Also solid.

That the driver was on duty rather than off, if they recorded it that way — which is a declaration, not a measurement.

What it does not show: that the wait was the facility's fault, that loading had not begun, that the driver was available and ready. Those are the facts a detention claim actually turns on, and the ELD is silent on all of them.

The trap for carriers

On-duty not driving is a claim about the driver, not about the facility.

A driver who logs off duty during a long wait — to preserve the fourteen-hour clock, which is rational — has created a record that undermines the detention claim, because the log now says they were not working.

That is a genuine conflict between two systems with different purposes: hours-of-service management pushes toward off duty, and detention documentation pushes toward on duty. Nobody has reconciled them, and drivers resolve it case by case under pressure.

If your operation bills detention, the policy on this needs to be explicit and written down, because the default is each driver deciding differently.

The known gaps

For completeness, since ELD data is sometimes treated as unimpeachable.

Unassigned driving time, if a carrier does not monitor and attribute it. Personal conveyance, where a driver switches status once available hours run out — FMCSA has acknowledged the potential for misuse and noted the mandate at least makes it more measurable than paper did. Yard moves. And multi-driver login arrangements.

None of these bears directly on detention claims. They matter because a record derived from an ELD is strong evidence and not automatic truth.

What to pair it with

A geofence event from a separate system, giving arrival independent of the driver's status choice.

A facility record — gate-in, check-in — which is what the other side will produce anyway. Two independent sources beat one authoritative one.

And a notification at free-time expiry, timestamped, which converts the ELD's location record into a documented event with the receiver's knowledge — the segments it cannot see are in the yard.

The short version