An electronic logging device (ELD) connects to the truck's engine and automatically records driving time for your Hours-of-Service logs. For most interstate CDL drivers who must keep records of duty status, an ELD is mandatory.
1. What it records
Driving time is captured automatically from vehicle movement. Your duty status (on duty, off duty, sleeper berth), location at duty changes, engine hours and miles are logged with it. You annotate and certify your logs; you can't erase driving time.
2. What's on you
- Pick the right status. The device knows when the wheels turn — it doesn't know you're off duty at a dock unless you tell it.
- Know your displays. At a roadside inspection you must be able to show your logs and transfer them to the officer.
- Carry the backup kit: the device's instruction sheet and blank paper logs in case of a malfunction.
- Review before you certify. Unassigned driving time and editing rules are specific — your carrier's policy adds its own requirements.
3. Why it helps you
Clean, automatic logs protect you in disputes, make your available hours visible at a glance, and feed the planning tools that keep you out of trouble — like our trip planning calculator.
See the current device list and rules at the official FMCSA ELD site, and learn the underlying limits in the HOS guide.