The HOS rules are the framework that decides how many hours a driver can be on the road in a day, in a week, and how rest is allocated between work periods. Most of the published material on HOS is either too dense (the regulatory text itself) or too oversimplified (driver forums) to actually help a new driver understand the math. The structure is genuinely manageable once you see it as three overlapping limits that all have to be true at the same time. Once you understand which limit is biting on any given day, planning the work around them stops feeling like guesswork.
The three core limits for property carriers
Under federal HOS rules for property-carrying commercial motor vehicles, three clocks govern your driving:
1. The 11-hour driving limit. You can drive a maximum of 11 hours after 10 consecutive hours off duty.
2. The 14-hour on-duty limit. Your driving must occur within a 14-hour window that starts when you go on duty. Once you've been on duty for 14 hours, you can't drive anymore until you've had 10 consecutive hours off duty — even if you haven't actually driven 11 hours yet.
3. The 60/70-hour limit. You can't drive after being on duty for 60 hours in 7 consecutive days, or 70 hours in 8 consecutive days. (Carriers using the 7-day rule operate on 60/7; carriers using the 8-day rule, which most OTR operations do, are on 70/8.)
All three limits run simultaneously. Whichever one hits first stops you.
How the 11-hour rule actually works
The 11-hour clock starts when you start driving after a 10-hour reset and continues counting actual driving time. Off-duty time, sleeper berth time, and on-duty-not-driving time (loading, fueling, paperwork) don't add to the 11.
So a typical day might look like:
- 06:00 Start of duty
- 06:30 Pre-trip and dispatch (on-duty, not driving — doesn't count against 11)
- 07:00 Start driving
- 11:00 4 hours driving completed
- 11:30 Fuel and lunch (off-duty — doesn't count against 11)
- 12:30 Resume driving — 4 hours driving still on the clock
- 16:30 8 hours driving completed
- Need to take 30-minute break before further driving
- 17:00 Resume after break
- 20:00 11 hours driving completed — driving must stop
After 11 driving hours, you can't drive until 10 consecutive hours off duty. You can still work on-duty (paperwork, loading, etc.) for the remainder of the 14-hour window, but no more driving.
How the 14-hour rule actually works
The 14-hour window starts the moment you go on duty after your 10-hour reset. It's a calendar clock — actual elapsed time from when duty starts.
Importantly: the 14-hour clock doesn't pause for off-duty time during the day (with limited sleeper berth exceptions). If you start at 06:00 and take a 4-hour break at noon, your 14-hour clock still expires at 20:00, even though you've only been "working" for 6 hours of that span.
This is the rule that catches new drivers. They take a long break in the middle of the day thinking it gives them more driving time later, and it doesn't. The 14 hours expire at 20:00 regardless.
The 30-minute break
After 8 cumulative driving hours without at least a 30-minute non-driving break, you have to take a 30-minute non-driving break before driving again. The break can be:
- Off-duty
- Sleeper berth
- On-duty-not-driving (since a 2020 rule change)
Most drivers take it during a fuel stop or a lunch break. The break has to be 30 consecutive minutes — you can't piece it together from shorter rests.
If you exceed 8 cumulative driving hours without taking the break, you're in violation even if you stop and take the break a few minutes later. The clock cares about the consecutive driving threshold.
The 60/70-hour rule
This rule prevents extended sustained operation across multiple days. You can't drive after being on duty for:
- 60 hours in any 7 consecutive days, or
- 70 hours in any 8 consecutive days
Carriers choose one or the other based on their operation. Most OTR carriers operate on 70/8.
The clock counts on-duty hours, not driving hours. So even if you only drove 4 hours yesterday but were on duty for 12 (waiting at a shipper, doing paperwork, etc.), all 12 count toward the 70/8.
The number you have available depends on your rolling 7 or 8 days. To get more hours back, you need to either let days fall off the rolling window or take a 34-hour restart.
The 34-hour restart
A 34-hour restart is 34 consecutive hours off duty (or in sleeper berth) that "resets" the 60/70-hour clock. After a 34-hour restart, your 7 or 8 day window restarts.
Restart requirements:
- 34 consecutive hours off duty or sleeper berth
- Has to be a true continuous rest period — no on-duty interruptions
Some additional limits on restarts from various versions of the regulation:
- Some operations have a once-per-7-days limit on using restarts
- Some have a 1 a.m. - 5 a.m. requirement on the rest hours (this rule has been in and out of effect)
The current standard restart is just 34 consecutive hours off duty with no additional time-of-day requirements for most carriers in 2026, but verify the current rule before relying on it.
Sleeper berth provisions
Drivers using a sleeper berth in a truck equipped with one can split their 10-hour off-duty period using the sleeper berth provision:
Split: 8 hours sleeper + 2 hours off-duty (or sleeper) = combined to satisfy 10-hour requirement.
The 8/2 split lets a driver take a short break (the 2-hour portion) without losing their full reset. The 14-hour clock pauses during the qualifying 8-hour sleeper berth period, which effectively extends the driving day.
A typical sleeper berth split day:
- 06:00 Start
- 14:00 8 hours of sleeper berth (clock pauses)
- 22:00 Resume duty — 14-hour clock picks up where it paused
- Drive until 11 hours driving or 14 hours on-duty (post-pause) is reached
The sleeper berth rules have evolved over the years and the math is fiddly. Most ELDs handle the calculation automatically once you log into sleeper berth properly. Manual calculation is error-prone enough that experienced drivers don't try to do it without ELD assistance.
The "adverse conditions" exception
If you encounter unforeseen adverse driving conditions (severe weather, accidents on the road, road closures), you can extend your driving time by up to 2 hours to complete the run. The exception is bounded:
- Must be genuinely unforeseen at the start of the day
- Limited to 2 additional driving hours
- Doesn't extend the 14-hour on-duty window beyond 2 hours
The adverse conditions exception isn't a routine workaround for tight schedules — it's for genuine unanticipated weather and incident events.
How the rules apply in real operation
In practice, a typical OTR driver running long hauls bumps against:
- The 14-hour clock most often — it's the most rigid because off-duty time during the day doesn't pause it.
- The 70-hour weekly limit for drivers doing back-to-back long days.
- The 11-hour driving limit least often, because the 14-hour clock usually expires first on a long day.
Strategic drivers manage to the 14-hour clock first, then the 70-hour clock, with the 11-hour limit as a secondary consideration.
Honest caveat: the rules have changed multiple times and continue to evolve
HOS regulations have been amended significantly several times since the 2003 rewrite. The 30-minute break rules changed in 2020. Personal conveyance guidance changed. The restart provisions have had iterative changes. New carriers reading older trucker forum posts or YouTube videos about HOS are sometimes working from rules that aren't currently in effect. The authoritative source is FMCSA's current published summary and 49 CFR Part 395 itself. Major operational decisions — like whether to use the sleeper berth split, whether you're eligible for short-haul exemption, whether your operation falls under the 60/7 or 70/8 — should be confirmed against the current regulation, not against older anecdotal sources. Specific edge cases (oilfield exemptions, certain agricultural operations, certain HHG configurations) have their own rules and the general HOS overview doesn't capture them.
The HOS framework is the constraint that shapes most of OTR planning. Internalizing the three core clocks — 11, 14, 70 — and knowing which one is going to expire first on any given day is the operational instinct that experienced drivers develop in their first six months.
Where this fits in the compliance picture
HOS compliance gets recorded by the ELD, reviewed at every roadside inspection, and audited by FMCSA against your supporting documents. It sits alongside the rest of the authority and compliance footprint — drug and alcohol program, BOC-3, UCR, MCS-150, IFTA — that any operating motor carrier has to maintain. If you would rather hand that broader footprint to a partner who stands it up and keeps it current, have us handle your authority.