Hours of Service Rules: Complete Guide for Fleet Managers

HOS rules cap driving time. Violate them and you're looking at fines, out-of-service orders, and CSA hits that stick around for 24 months.

FMCSA's Hours of Service regulations (49 CFR Part 395) limit how long CMV drivers can operate before they must rest. For property-carrying vehicles, the core limits are the 11-hour driving limit, 14-hour on-duty window, mandatory 30-minute break, and a 60/70-hour cumulative cap.

The Core HOS Rules for Property-Carrying CMVs

These federal rules apply to drivers of trucks, tractor-trailers, and other property-carrying CMVs in interstate commerce.

1. 11-Hour Driving Limit

A driver can drive a maximum of 11 hours after 10 consecutive hours off duty. Use all 11 and the driver must take another 10 consecutive hours off before driving again. No exceptions.

Driving time means any time the vehicle is in motion. The ELD tracks it automatically based on vehicle speed and engine status.

2. 14-Hour On-Duty Window

All driving must happen within a 14-hour window that starts when the driver first comes on duty or begins driving (whichever is first) after a qualifying 10-hour off-duty period.

The 14-hour clock doesn't pause. Loading, fueling, paperwork, waiting at a shipper, meals — all of it eats the window. Once it closes, the driver can't drive again until they've taken another 10 consecutive hours off.

And this rule creates the most operational friction of any HOS provision. A driver on duty at 6:00 AM has until 8:00 PM to finish all driving, regardless of how much actual driving time they've used. Detention at a shipper eats hours that never come back.

For a detailed look at how the 11-hour and 14-hour rules interact, see How the HOS 11-Hour and 14-Hour Rules Work Together.

3. 30-Minute Break Requirement

After accumulating 8 hours of driving time, a driver must take at least 30 consecutive minutes off.

The September 2020 final rule loosened this considerably. The break can now be satisfied by 30 minutes of off-duty time, sleeper berth time, or on-duty not-driving time. Before that change, only off-duty or sleeper berth time counted — which was a real headache for a lot of operations.

A driver at 7 hours and 45 minutes of driving can satisfy the break by spending 30 minutes at a loading dock (on-duty not-driving). No need to go fully off duty.

4. 60-Hour/7-Day and 70-Hour/8-Day Limits

A driver can't be on duty for more than:

• 60 hours in any 7 consecutive days (carriers that don't operate every day), or
• 70 hours in any 8 consecutive days (carriers that operate daily)

These are rolling limits. Each day, the oldest day drops off and the current day gets added. The math is simple. Tracking it across dozens of drivers is not.

You choose which limit applies. The majority of long-haul operations go with 70/8.

5. 34-Hour Restart

Once a driver hits the 60/70-hour limit, they can reset to zero by taking at least 34 consecutive hours off duty. After a qualifying restart:

• The 60/70-hour clock resets to zero
• There's no limit on how often a driver can use this
• The restart doesn't need to include any specific time of day. The 2013 provisions requiring two 1:00 AM–5:00 AM periods were suspended and never came back.

“The 34-hour restart is the most operationally significant HOS provision for long-haul fleets. A driver who runs out of hours on Friday can restart Saturday morning and have a full 70-hour bank by Sunday night. Plan your schedules around it.”

Sleeper Berth Provisions

Drivers in a vehicle with a sleeper berth can split their required 10 hours of off-duty time under 49 CFR §395.1(g). There are two options, and both are worth understanding even if your fleet mostly runs day cabs:

Split Option 1: 7/3 Split

• At least 7 consecutive hours in the sleeper berth, plus
• At least 3 consecutive hours off duty, in the sleeper berth, or a combination

Split Option 2: Flexible Split

The 2020 final rule allows any combination of two periods totaling at least 10 hours, where:

• One period is at least 7 hours in the sleeper berth
• The other is at least 2 hours off duty, in the sleeper berth, or a combination
• Neither period counts against the 14-hour window

That last point is critical. A qualifying split effectively extends the calendar day for team and long-haul operations.

Passenger-Carrying CMV Rules

Passenger-carrying CMV drivers (buses, motorcoaches) operate under different limits:

September 2020 HOS Final Rule Changes

The most recent major HOS change took effect September 29, 2020. Make sure your policies reflect these updates:

1. 30-minute break flexibility. On-duty not-driving time now counts for the 30-minute break.
2. Short-haul radius increase — CDL short-haul exemption went from 100 air miles to 150 air miles
3. Sleeper berth split flexibility: the shorter split period minimum dropped from 3 hours to 2 hours
4. Adverse driving conditions. Drivers can extend the driving limit by up to 2 hours (13 total) when they hit adverse conditions not known before departure.

Adverse Driving Conditions Exception

The conditions must not have been reasonably foreseeable at departure. A driver who leaves knowing a severe storm is in the forecast cannot claim this exception — and inspectors will check weather records to verify.

When qualifying adverse conditions do arise (weather, road closures, traffic incidents unknown before departure), 49 CFR §395.1(b)(1) allows a driver to:

• Extend the driving limit by up to 2 hours (11 to 13)
• Extend the 14-hour window by up to 2 hours (to 16)

HOS Violations and CSA Impact

HOS violations are among the most common findings at roadside inspections. They hit the Hours-of-Service Compliance BASIC in your CSA profile, where the intervention threshold sits at the 65th percentile. FMCSA acts at a lower threshold here than for most other BASICs, which means it doesn't take much to end up on their list.

Common violations inspectors find:

For detailed information on ELD enforcement and penalties related to HOS, see ELD Violations: Fines, Process, and Prevention.

Managing HOS Compliance Across Your Fleet

Knowing the rules isn't enough. Good HOS management means operational systems that prevent violations before they happen.

Monitor HOS-related violations through FMCSA data. Hours-of-service violations show up in roadside inspection data and can affect your Hours-of-Service Compliance BASIC.

Use CSA and inspection insights to spot trends early. If HOS violations start stacking up, that’s your signal to coach drivers, review schedules, and tighten internal processes before problems snowball.

Train around the most common risk areas. Make sure drivers and managers understand the 11-hour, 14-hour, break, and 60/70-hour rules so violations don’t start showing up in your safety profile.

Foley's Dash platform helps carriers stay on top of broader compliance by bringing together DOT drug testing, driver qualification files, and CSA score management — giving teams a clearer view of issues, including roadside violations that can impact their safety profile.

Request a demo to see how it works.