Truck & Car Guides / Trucking life & careers
Electronic logging devices (ELDs)
ELDs replaced paper logbooks for most US truck drivers. What they record, how they work, who is exempt and what drivers should know about using them.
From paper to electronic
For decades truck drivers kept their hours of service on paper logbooks, drawing lines across a grid for each duty status. Paper logs were easy to fudge, and enforcement was difficult. Congress required electronic logging, and the FMCSA's ELD rule took effect on December 18, 2017. Carriers already using older automatic onboard recording devices (AOBRDs) had until December 16, 2019 to switch to compliant ELDs.
What an ELD records
An ELD connects to the truck's engine control module, usually through a diagnostic port, and automatically records:
- Date and time
- Location (general position, not precise tracking for the log record)
- Engine hours and vehicle miles
- When the vehicle is moving and when it stops
- Driver identification and the carrier's information
When the truck starts moving above a low speed threshold, the ELD automatically switches the driver to driving status. The driver selects other statuses such as off duty, sleeper berth or on duty not driving.
What the driver sees
Most ELDs run on a tablet or phone mounted in the cab. They show countdown clocks for:
- Driving time left in the 11-hour limit
- Time left in the 14-hour window
- Time until the 30-minute break is required
- Hours available in the 60/70-hour cycle
This makes hours-of-service rules much easier to follow.
Edits and annotations
Drivers can correct mistakes, such as forgetting to switch to on duty while fueling, but the original record is kept. Edits must be annotated with a reason and the driver must certify their logs. Carriers can propose edits, but the driver has to accept them. This protects against pressure to falsify.
Roadside inspections
At an inspection, the officer can view logs on the screen or receive them electronically through a data transfer. Drivers are generally required to carry an ELD user manual, an instruction sheet for data transfer, an instruction sheet for reporting malfunctions, and a supply of blank paper log sheets for at least 8 days in case the device fails.
Who is exempt
General exemptions include:
- Drivers operating under the short-haul exception who are not required to keep logs.
- Drivers who need logs on no more than 8 days in any rolling 30-day period.
- Drivers in drive-away/tow-away operations where the vehicle being driven is the commodity.
- Vehicles with engines older than model year 2000.
Check FMCSA guidance for the exact current conditions.
Malfunctions
If the ELD fails, the driver should note the malfunction, notify the carrier within a short period and reconstruct logs on paper for the current day and prior days as required. The carrier then has a limited time to repair or replace the device.
Pros and cons drivers mention
| Pros | Cons |
|---|---|
| Less paperwork | Less flexibility around tight schedules |
| Fewer form-and-manner violations | Clock keeps running during long waits at docks |
| Easier inspections | Connectivity issues in remote areas |
| Clear clocks make planning easier | Some drivers feel watched |
Plan your day backwards from your 14-hour window. If a shipper keeps you waiting, the ELD will not pause the clock, so build buffer time into delivery appointments.
Official source
See the FMCSA's ELD program for the list of registered devices, rule text and FAQs. This guide is general education only.
