An electronic logging device (ELD) is a device that connects to a commercial vehicle’s engine and automatically records when it is being driven, so the driver’s hours of service (the limits on driving and on-duty time) are logged electronically instead of in a paper logbook. The driver signs in, changes duty status (on duty, off duty, sleeper berth) on a screen or app, and the device captures driving time from the engine itself. Inspectors can view or receive the logs during a roadside check, and the fleet can review them in software. In the US and Canada, regulations require many commercial fleets to use one; the exact rules depend on where and how you operate.
At a glance
- An ELD records driving time from the engine, so the log reflects when the vehicle actually moved.
- It is defined by a regulator’s technical requirements, not by a feature list; many telematics products include ELD functions.
- The ELD mandate is the regulation that requires the device; who must comply, and which exemptions apply, varies by country.
- Logs are shared with roadside inspectors in the formats the regulator specifies.
- Fleets usually buy ELDs as a monthly subscription with hardware, often bundled with GPS tracking.
What problem it solves
Paper logbooks are slow, easy to get wrong and easy to falsify. Errors lead to violations at roadside inspections, and dispatchers have no reliable view of how many hours a driver has left before assigning the next load. An ELD records driving time automatically, flags drivers approaching their limits, and keeps a record that is harder to edit after the fact, since changes are typically tracked and attributed.
For the fleet, the benefit goes beyond compliance. Accurate hours data supports dispatch planning, payroll for hourly drivers, and fewer out-of-service orders. Because most ELDs also collect location and engine data, they often become the backbone of a wider fleet telematics program.
How it works
Engine connection. The device plugs into the vehicle’s diagnostic port or engine control module and reads data such as engine on/off, vehicle motion, miles and engine hours. When the vehicle moves above a set speed, the ELD switches the driver to driving status automatically.
Driver interface. Drivers log in and change duty status on a dedicated display, a tablet or a phone app paired with the device. Some setups let the driver annotate or correct entries; edits are typically recorded and may need the driver’s approval.
Back office. Logs sync over cellular to the provider’s platform, where safety and compliance staff review hours, violations, unassigned driving time and supporting documents.
Roadside transfer. At an inspection, the driver displays the logs or sends them to the inspector using the transfer methods the regulator allows.
Certification. In the US, providers self-certify their devices and the regulator keeps a list of registered ELDs, which can be revoked. Canada uses third-party certification. Other countries have their own regimes or none, so check locally.
Our Fleet Management solution page covers how to compare ELD, telematics and camera providers together.
When it matters for buyers
- You run vehicles subject to hours-of-service rules. Confirm which drivers and vehicles are covered and which exemptions apply.
- Your current device is being retired or deregistered. Replacement timelines can be short.
- You are consolidating fleet vendors. ELD, GPS tracking and video telematics are often bought from one provider; compare bundled and separate options.
- You are expanding across borders. US and Canadian requirements differ, and a device certified for one may not meet the other.
- At contract renewal. Hardware, monthly fees and data plans are all negotiable, and multi-year terms may lock in devices you will want to replace.
Questions to ask vendors
- Is the device registered or certified for each jurisdiction where our vehicles run?
- What happens to us if the device is removed from the regulator’s list, and who pays for replacement?
- Which vehicles, engines and model years are supported, and how is the device installed?
- How do drivers transfer logs at an inspection, and what training do you provide?
- What cellular network does the device use, and what happens when a vehicle loses coverage?
- Is the ELD sold alone or only with a telematics bundle, and what does each cost per vehicle per month?
- Can we export our hours-of-service records if we switch providers, and in what format?
How it differs from fleet telematics
Fleet telematics is the broad practice of collecting location, engine and driver data from vehicles to run the fleet better. An ELD is a specific regulated device whose required job is logging hours of service. Many telematics units include ELD functions, and many ELDs collect telematics data, so they often arrive as one product. The difference matters when you compare quotes: confirm that the ELD part meets the rules where you operate, and judge the telematics features on their own merits as part of your wider fleet management plan.