CDL Log Books and ELDs Explained
Updated June 2026
How many hours can you still drive?
Log books track your hours of service so you (and inspectors) can see you're driving legally. Most drivers now log electronically with an ELD. Here's how it works.
The four duty statuses
- Off duty — not working, free time.
- Sleeper berth — resting in the truck's sleeper.
- Driving — at the controls, vehicle moving.
- On duty (not driving) — working but not driving: fueling, loading, inspections, paperwork.
Your day is a record of these statuses, and they feed the hours-of-service limits (11-hour, 14-hour, etc.).
What an ELD does
An Electronic Logging Device connects to the engine and automatically records driving time, making logs harder to falsify than old paper books. You still set the non-driving statuses and certify each day. Since the ELD mandate, most interstate drivers must use one.
Who is exempt
Some drivers don't need an ELD, including certain short-haul drivers (who stay within a set radius and hours and use time cards), drivers of pre-2000 engine trucks, and a few other limited cases. Even if exempt from the ELD, you still follow the hours-of-service limits.
Supporting documents
Keep supporting documents (fuel receipts, bills of lading, etc.) — they back up your logs during an audit. Accurate logs protect your CDL: falsifying them is a serious violation.
Not sure how much driving time you have left? The HOS calculator below does the math from your day so far.
How many hours can you still drive?
Frequently asked questions
Do all truckers need an ELD?
Most interstate CMV drivers do, but there are exceptions — short-haul drivers within limits, trucks with pre-2000 engines, and a few others. They still must follow HOS rules.
What are the four duty statuses?
Off duty, sleeper berth, driving, and on duty (not driving). Your logs record time in each.