CDL Hours of Service Rules Explained: Every Clock, in Plain English

Quick answer: After 10 consecutive hours off duty, a property-carrying driver may drive up to 11 hours inside a 14-consecutive-hour window, must take a 30-minute break before driving past 8 cumulative hours of driving, and may not drive after reaching 60 hours on duty in 7 days (or 70 in 8 days for carriers operating every day). The rules live in 49 CFR Part 395.

Regulatory-change disclaimer: Hours-of-service rules change through rulemaking, exemptions, and guidance. This page was last reviewed on July 17, 2026 against the eCFR. Confirm the current text of 49 CFR Part 395 on ecfr.gov and FMCSA's HOS summary before relying on it. Nothing on this page is legal advice.

What "hours of service" means

Hours of service (HOS) are the federal limits on when and how long you may drive a commercial motor vehicle (CMV). The Federal Motor Carrier Safety Administration (FMCSA) publishes them in 49 CFR Part 395. Your electronic logging device (ELD) exists to record your duty status against these limits — the limits themselves come from the regulation, not the device.

Every minute of your work day falls into one of four duty statuses: off duty, sleeper berth, driving, and on duty (not driving). Every HOS rule is arithmetic over those four statuses.

Why the rules exist

Part 395 is a fatigue rule. Driving performance degrades with time behind the wheel and time since real rest, and a loaded combination vehicle leaves no margin for a driver who is asleep at 65 mph. The limits force rest before the fatigue, not after the crash.

Who must follow these rules

Federal requirement: The property-carrier HOS rules apply to drivers of CMVs in interstate commerce, as defined in 49 CFR 390.5. That generally means:

• vehicles with a gross vehicle weight rating or gross combination weight rating of 10,001 pounds or more
• vehicles placarded for hazardous materials
• certain passenger configurations (passenger carriers follow their own limits in 395.5)

Intrastate-only drivers follow their state's version of the rules — often similar, never guaranteed identical. Check your state.

The four core limits, step by step

1. The 11-hour driving limit

After 10 consecutive hours off duty, you may drive a total of 11 hours. Driving time is time at the controls. Full article: The 11-Hour Driving Limit. Citation: 49 CFR 395.3(a)(3).

2. The 14-hour driving window

Once you come on duty after 10 consecutive hours off, a 14-consecutive-hour clock starts. You may not drive after that window closes, no matter how little you drove — breaks and lunches do not stop it. Full article: The 14-Hour Driving Window. Citation: 49 CFR 395.3(a)(2).

3. The 30-minute break

You may not drive once you have accumulated 8 hours of driving time without at least a 30-minute non-driving interruption. Since the 2020 rule change, on-duty-not-driving time can satisfy the break. Full article: The 30-Minute Break Rule. Citation: 49 CFR 395.3(a)(3)(ii).

4. The 60/70-hour limits

You may not drive after 60 hours on duty in any 7 consecutive days (carriers that do not operate every day of the week) or 70 hours in 8 consecutive days (carriers that do). Taking 34 or more consecutive hours off duty restarts the 7/8-day calculation. Citation: 49 CFR 395.3(b) and (c).

The flexibilities that sit on top

• Split sleeper berth — split your 10 hours off into a 7/3 or 8/2 pairing, with the qualifying periods excluded from the 14-hour window. Full article: Split Sleeper-Berth Rules. Citation: 49 CFR 395.1(g).
• Adverse driving conditions — up to 2 extra hours of driving time and window when you hit weather or road conditions you could not have known about before dispatch. Citation: 49 CFR 395.1(b)(1).
• Short-haul exception — drivers who stay within a 150 air-mile radius and meet the return-to-base and 14-hour conditions of 49 CFR 395.1(e)(1) can run without ELDs or the 30-minute break.
• Personal conveyance and yard moves — two ELD driving categories that move the truck without spending your driving clocks the same way. Full articles: Personal Conveyance Explained and Yard Move Explained.

A compliant day, worked example

Example (illustration, not legal advice): You had a full 10-hour break and come on duty at 05:00 for a pre-trip inspection. Your 14-hour window runs 05:00–19:00.

• 05:00–06:00 — on duty, pre-trip and paperwork (1 window hour used, 0 driving)
• 06:00–10:00 — drive 4 hours (4 of 11 used)
• 10:00–10:30 — 30-minute break (satisfies the break rule before you reach 8 cumulative driving hours)
• 10:30–14:30 — drive 4 more hours (8 of 11 used)
• 14:30–15:30 — on duty, unload (no driving)
• 15:30–18:30 — drive 3 hours (11 of 11 used)

At 18:30 the driving limit is exhausted, half an hour before the window closes at 19:00. Every number above checks out against 395.3: 11 driving, inside 14, break taken before the ninth cumulative driving hour.

Common mistakes

• Treating the 14-hour window like a driving clock that pauses for lunch — it never pauses (only qualifying sleeper-berth periods are excluded).
• Assuming on-duty work after the 14th hour is a violation — it is not; only driving past the limits is prohibited, though the on-duty time still counts against 60/70.
• Confusing the 8-hour break trigger (cumulative driving hours) with 8 hours since the shift started.
• Running a 34-hour restart when the 60/70 math did not require one — the restart is optional recovery, not a weekly obligation.
• Copying another driver's interpretation of a carrier policy as if it were the federal rule. Company policies can be stricter than Part 395 — they can never make Part 395 looser.

Violations and compliance risks

HOS compliance is checked at roadside inspections and during carrier investigations, using your ELD records. Violations are recorded on the inspection report, feed the FMCSA Safety Measurement System scores that follow both driver and carrier, and can result in a driver being placed out of service under the CVSA North American Standard Out-of-Service Criteria until enough off-duty time passes. For current enforcement specifics, rely on FMCSA and CVSA — not forum lore.

Driver checklist

• Know your four clocks before you turn the key: driving hours left, window hours left, cumulative driving since your last 30-minute break, and 60/70 hours left.
• Log your duty status changes as they happen, not at the end of the day.
• Plan the 30-minute break into the trip instead of donating it to a shipper's dock line.
• Before using a flexibility (split berth, adverse conditions, personal conveyance), be able to say which rule allows it and where it is written.
• When your ELD and your memory disagree, investigate immediately — see ELD Malfunctions and What Drivers Must Do.

Keep learning

• Deep dives: 11-hour limit · 14-hour window · 30-minute break · split sleeper · personal conveyance · yard moves · ELD malfunctions
• Getting inspected: Level 1 DOT Inspection Explained
• Test yourself free: the CDL General Knowledge practice test covers hours-of-service questions, and the practice test hub has every bank.
• Watch: FMCSA Just Changed DOT Inspections on the Trucking Life with Shawn YouTube channel.
• Want a career built on doing this right? Train with us at the TLWS Academy, start free with CDL Pre-School, or join the email list for new guides as they publish.