Hours of service (HOS): The Basics

Commercial truck drivers in the United States operate under federal rules that control how many hours they can drive and work in a single day and across a rolling week. These rules — known as hours of service (HOS) — are enforced by the Federal Motor Carrier Safety Administration (FMCSA) under 49 CFR Part 395.

The reason these limits exist is simple: a fatigued driver is a dangerous driver. HOS rules set mandatory rest periods to ensure drivers are rested before getting back behind the wheel.

Most drivers subject to HOS rules are required by the ELD mandate to record their duty time using a certified electronic logging device (ELD). An ELD connects to the vehicle's engine and automatically captures driving activity, replacing paper logbooks. Paper logs are still permitted in a small number of exempted situations.

Understanding these rules matters for everyone on your team — drivers avoid violations and out-of-service orders, fleet managers protect their safety rating, and carriers stay in good standing with shippers and enforcement.

Which drivers must follow HOS rules?

HOS rules apply to drivers and carriers operating CMVs in interstate commerce. Your vehicle is a CMV if it meets any one of the following (49 CFR § 390.5):

• Weighs 10,001 lbs or more (GVWR or GCWR)

• Carries 9 or more passengers for compensation

• Carries 16 or more passengers without compensation

• Transports hazardous materials requiring a placard

How daily driving limits work?

Three clocks run simultaneously during your shift: a driving clock, a shift clock, and a weekly clock. Understanding all three is essential — a violation occurs the moment any one of them is exceeded.

The 11-hour driving limit

You may drive a maximum of 11 hours in a 14-hour shift, but only after taking at least 10 consecutive hours off duty to start (49 CFR § 395.3(a)(3)(i)).

The 14-hour on-duty window

Think of the 14-hour window as a running clock. It starts the moment you go on duty and counts down for exactly 14 working hours — whether you are driving, doing paperwork, eating, or waiting at a dock. When it reaches zero, you cannot drive again until you have taken at least 10 consecutive hours off duty (49 CFR § 395.3(a)(2)).

Within that window, you may drive up to 11 hours. You do not have to use all 11 — but any driving must happen before the window closes.

The 30-minute break

After 8 cumulative hours of driving, you must take at least 30 consecutive minutes off driving before you can drive again. The break can be logged as off duty, sleeper berth, or on-duty not driving (49 CFR § 395.3(a)(3)(ii)).

The 60/70-hour weekly limit

Regardless of your daily hours, you cannot drive once your total on-duty time across the rolling week reaches your carrier's limit (49 CFR § 395.3(b)):

Your carrier's schedule determines which limit applies — not your own driving schedule. The cycle rolls forward daily, dropping the oldest day and adding the new one.

Example of 70-hour / 8-day cycle limit

The 34-hour restart

Once you hit your weekly limit, you can reset it to zero by taking at least 34 consecutive hours off duty (49 CFR § 395.3(c)).

Sleeper berth provision

If your truck has a sleeper berth, you can split your required 10 hours of off-duty rest into two separate periods instead of taking them all at once. This gives long-haul drivers more flexibility when planning rest around traffic and delivery windows (49 CFR § 395.1(g)).

Requirements for a valid split:

• Neither period can be shorter than 2 consecutive hours

• One period must be at least 7 consecutive hours spent in the sleeper berth

• Both periods combined must total at least 10 hours

The two most common configurations are:

• 7/3 split — 7 consecutive hours in the sleeper berth, plus at least 3 hours off duty or in the sleeper berth

• 8/2 split — 8 consecutive hours in the sleeper berth, plus at least 2 hours off duty or in the sleeper berth

The 14-hour window pauses during the shorter rest period and resumes from where it left off. Driving hours accumulated on both sides of the split count together against your 11-hour limit.

Example of 7/3 split rule

Which HOS exemptions apply to you?

Several exemptions change or remove HOS requirements for specific types of operations. Using an exemption you do not qualify for — even if your logged hours look fine — can still result in a violation.

Short-haul exemption — CDL drivers

CDL drivers who stay close to their home terminal and return each day may be exempt from the ELD requirement and daily log (49 CFR § 395.1(e)(1)).

You qualify if all of the following apply:

• You operate within 150 air miles (172.6 statute miles) of your normal work location

• You return and are released from duty within 14 consecutive hours

• You take at least 10 consecutive hours off before your next shift

The 11-hour driving limit and 14-hour window still apply. Only the ELD and daily log requirements are removed.

Short-haul exception — non-CDL drivers

Non-CDL drivers who operate within 150 air miles and meet the same return conditions can extend their on-duty window from 14 to 16 hours up to two days per week (49 CFR § 395.1(e)(2)). The 11-hour driving limit does not change.

To remain eligible, you must use the standard 14-hour window for at least 5 of every 7 consecutive days.

Adverse driving conditions exemption

If you encounter unexpected severe weather or road conditions after your trip has already started, you may drive up to 2 additional hours (49 CFR § 395.1(h)(1)):

• Driving limit extends from 11 to 13 hours

• On-duty window extends from 14 to 16 hours

Qualifying conditions (49 CFR § 395.2): sudden snow, ice, fog, or road closures that were not foreseeable before you left or before your last qualifying rest period.

How to document your HOS compliance?

Most CMV drivers must use a certified ELD to record duty status automatically. At a roadside inspection, you must display logs for the current day and the previous 7 days. Route One ELD makes this available in DOT Inspection Mode directly from the driver app — no printing required.

Your carrier must retain your logs for at least 6 months (49 CFR § 395.8(k)).

If you haven't set up your ELD yet, visit the Get Started collection first.