Trucking · Regulation
Hours of service.
The federal rules.
The Federal Motor Carrier Safety Administration writes the rules that govern how long a US commercial truck driver can drive before stopping, how long the day's driving window stays open, when a break is required, and how the weekly clock resets. The current rule set is codified at 49 CFR Part 395 Subpart A and was substantially reshaped by the September 29, 2020 final rule. Here is the rule, layer by layer, with the 2020 reform called out where it changed the prior framing.
Sibling pages: /trucking/eld/ for the recording-and-enforcement layer (Subpart B); /trucking/ for the section index.
1 · The rules
49 CFR Part 395 Subpart A
The federal hours-of-service rules are codified at 49 CFR Part 395 and apply to every driver of a commercial motor vehicle (CMV) operating in interstate commerce. They are written and enforced by the Federal Motor Carrier Safety Administration (FMCSA), the agency that sits next to the FAA under the US Department of Transportation and governs the surface-freight side of regulated transportation.
The current rule set is the product of five reform waves. The 2003 final rule replaced the 1937 framework with the 11-hour / 14-hour / 10-hour structure that still anchors the regime today. The 2011 final rule (issued after the Seventh Circuit's 2009 remand in OOIDA v. FMCSA) added the 30-minute break and the 34-hour restart's twice-per-week / two-consecutive-1am-5am constraints. The 2013 restart restrictions were suspended by Congress and ultimately rescinded. The September 29, 2020 final rule is the most recent substantive reshape: it expanded the short-haul exception, broadened the adverse-driving-conditions extension, added the 7/3 split-sleeper-berth option, and clarified the 30-minute break so any non-driving status counts.
The shape, top-down
- 11-hour driving limit — a driver may drive for up to 11 hours after 10 consecutive off-duty hours.
- 14-hour duty window — the 11 driving hours have to fit inside 14 consecutive hours of being on duty. Off-duty time inside the window does not extend it.
- 30-minute break — required after 8 cumulative driving hours without a 30-minute interruption.
- 60/70-hour weekly cap — no more than 60 on-duty hours in 7 days (carriers that don't run every day) or 70 in 8 days (carriers that do). A 34-hour restart resets the rolling clock.
On top of the four core rules sit five accommodations that modify or replace them in specific circumstances: the split sleeper berth (Section 6 below), the short-haul exception (Section 7), the agricultural commodity exception (Section 8), the adverse-driving-conditions extension (Section 9), and a small set of additional exceptions and special cases (Section 10). The substantive driving-time rules sit on one side of Part 395; the recording-and-enforcement layer — the Electronic Logging Device mandate under Subpart B — sits on the other. The sibling page at /trucking/eld/ covers the device side.
Scope
The HOS rules apply to drivers of commercial motor vehicles — not just CDL Class-A tractor-trailers. A CMV under 49 CFR § 390.5 is any vehicle with a gross weight or rating of 10,001 lbs or more, any vehicle designed to transport 9+ passengers for compensation (16+ not for compensation), and any vehicle hauling hazardous materials in placardable quantities. Passenger-carrying CMVs (buses) operate under a parallel-but-different ruleset at § 395.5; the property-carrying ruleset below is the focus of this page.
Several adjacent regulatory regimes ride alongside HOS without being part of it: CDL licensing at Part 383, drug-and-alcohol testing at Part 382, hazmat regulations at Parts 100–185, vehicle inspection at Part 396, and driver qualification at Part 391. Each will get its own sibling page under /trucking/ as the section grows.
For a quick orientation to the parallel regulated-transportation reference cluster on this site: the aviation regulatory-explainer page at /aviation/pilot-mentoring/ covers a similar shape on the airline side — one statute, one final rule, one CFR location, multiple advisory circulars, and a vendor landscape that grew up around the regulation.
2 · Driving time
The 11-hour limit
Under § 395.3(a)(3)(i), a property-carrying CMV driver may drive for a maximum of 11 hours after coming on duty following 10 consecutive hours off duty. The limit resets only when the next 10-consecutive-hour off-duty period (or a qualifying sleeper-berth split — see Section 6) completes. Off-duty time short of 10 consecutive hours does not reset the driving clock.
Two clarifications that visitors regularly ask about:
- “Driving time” means time at the wheel of the CMV. Time spent in the truck doing paperwork, fueling, inspecting, or waiting at a dock is on-duty-not-driving and does not consume the 11-hour clock (though it does consume the 14-hour window — see Section 3).
- The 11 hours are cumulative across the duty period, not consecutive. A driver can drive for 5 hours, take a 2-hour break, drive for another 5 hours, and still be inside the 11-hour limit (with 1 hour remaining), as long as the 14-hour window and the 30-minute-break rule are also satisfied.
Driving past the 11-hour limit is an out-of-service violation at roadside inspection and a carrier-side compliance violation under § 395.3. The driver is placed out of service until enough rest has accumulated; the carrier is scored for the violation under the Safety Measurement System.
3 · Duty window
The 14-hour rule
Under § 395.3(a)(2), a driver may not drive after the 14th consecutive hour after coming on duty following 10 consecutive off-duty hours. The 14-hour window starts running as soon as the driver comes on duty and runs continuously — off-duty time inside the window does not extend it. A driver who takes a 2-hour off-duty break in the middle of the day still has the same 14-hour window's end-time.
Two exceptions do extend the 14-hour window, and they are the only ones that do:
Qualifying sleeper-berth split
An 8/2 or 7/3 split (Section 6) pairs a longer sleeper-berth period with a shorter off-duty-or-sleeper period. Neither period counts against the 14-hour window — the window's end-time effectively slides forward by the length of the longer period in the pair.
Adverse-driving conditions
Up to 2 hours of extension to the 14-hour window when adverse weather or traffic conditions the driver couldn't have anticipated arise (Section 9). The 14-hour extension was added in the September 29, 2020 reform; prior to that, the adverse-conditions exception extended only the 11-hour driving limit.
Before vs. after 2020
Prior to September 29, 2020, the only extension to the 14-hour window was the sleeper-berth split (then 8/2 only). The adverse-conditions exception extended only the 11-hour driving limit, which created a recurring practical problem — a driver stopped by unexpected weather often ran out of driving window before running out of driving hours. The 2020 reform added the parallel 14-hour extension.
4 · 30-minute break
The cumulative-8-hour rule
Under § 395.3(a)(3)(ii), a driver who has accumulated 8 hours of driving time without a 30-minute interruption may not drive again until a 30-minute interruption has been taken. The break can be off-duty, in the sleeper berth, or on-duty-not-driving — any non-driving status qualifies. This is the rule's load-bearing 2020 change.
Before vs. after 2020
Under the pre-2020 rule, a 30-minute break had to be off-duty (or sleeper-berth) to satisfy the requirement — on-duty-not-driving time, such as the time spent waiting at a dock or supervising a load, did not count. The 2020 reform broadened the qualifying statuses to include any non-driving status. A driver waiting at a shipper's dock for 30+ minutes now satisfies the break automatically, where the pre-2020 framing would have required the driver to switch to off-duty status during the wait.
5 · 60/70-hour cap
The weekly rolling clock
Under § 395.3(b), a driver may not be on duty for more than 60 hours in any 7 consecutive days (for carriers that do not operate every day of the week) or 70 hours in any 8 consecutive days (for carriers that do). The cap applies to total on-duty time — driving plus on-duty-not-driving, not just driving.
The rolling-clock framing
The cap is rolling, not weekly. Each day at the start of the duty period, the driver looks back at the past 7 (or 8) days and totals the on-duty hours. The driver may go on duty today only if that running total plus today's expected on-duty time stays under 60 (or 70). The clock does not reset at midnight Sunday; it rolls continuously. This is the part visitors regularly misread — the 60/70 cap is not a Monday-to-Sunday weekly budget.
Under § 395.3(c), a driver may reset the rolling clock by taking 34 consecutive hours off duty. After a 34-hour restart, the driver's 7-day (or 8-day) on-duty count restarts at zero. The 2013 reform briefly added two extra restrictions on the restart (twice-per-week limit, two consecutive 1am-5am periods required); both were suspended by Congress in 2014 and ultimately rescinded.
- 60-in-7 — the cap for a carrier that does not operate every day of the week. A driver counts the trailing 7 days.
- 70-in-8 — the cap for a carrier that operates every day of the week. A driver counts the trailing 8 days.
- 34-hour restart — 34 consecutive off-duty hours resets the rolling clock to zero. Once-per-rolling-period restriction does not apply post-2014.
The carrier decides whether it operates “every day of the week” for purposes of the 60-vs-70 election. The decision is on the carrier's certificate; individual drivers within a carrier operate under whichever cap the carrier has chosen.
6 · Sleeper berth
The split sleeper-berth provision
Under § 395.1(g), a driver with access to a sleeper berth may satisfy the 10-consecutive-hour off-duty requirement by splitting it into two periods. The September 29, 2020 reform allows two valid splits: an 8/2 split (8 hours in sleeper berth plus 2 hours off-duty-or-sleeper) and a 7/3 split (7 hours in sleeper berth plus 3 hours off-duty-or-sleeper). The two periods must total at least 10 hours, the longer period must be in the sleeper berth, and neither period counts against the 14-hour driving window.
Before vs. after 2020
The 8/2 split has existed in some form since the 2005 rule; the 7/3 split is new in the 2020 reform. Adding the 7/3 option gave drivers a second valid split shape that fits a common real-world cadence (a longer mid-day rest plus a shorter overnight, or vice versa) which the 8/2 alone did not support cleanly. The 14-hour-window-pause mechanic is the rule's load-bearing feature in either split — the driver effectively gets a longer driving day because neither qualifying rest period consumes window time.
7 · Short-haul
The 150 air-mile exception
Under § 395.1(e)(1), a driver who operates within a 150 air-mile radius of the normal work-reporting location, returns to that location at the end of each duty period, and stays on duty no more than 14 hours is excepted from the records-of-duty-status (RODS) and Electronic Logging Device requirements. The carrier must maintain a timecard-style record of the driver's start time, end time, and total on-duty hours for six months.
The work-reporting-location concept
The exception is anchored to the driver's normal work-reporting location — the place the driver normally starts and ends the duty period. A driver operating out of a single terminal qualifies cleanly; a driver who reports to different terminals on different days has to evaluate the exception per duty period, against whichever terminal the driver reported to that day. The 150 air-mile radius is measured as a straight-line air distance, not by the road network.
Before vs. after 2020
Before September 29, 2020, the property-carrying short-haul exception was 100 air-miles and 12 hours on-duty. The 2020 reform expanded the radius to 150 air-miles and the duty period to 14 hours, aligning the short-haul exception with the standard 14-hour window. The expansion materially enlarged the population of drivers eligible to operate under the exception (and therefore exempt from RODS / ELD recordkeeping).
Drivers using the short-haul exception still have to comply with the substantive driving-time rules (11-hour driving limit, 14-hour duty window, 60/70-hour weekly cap, the 30-minute break). The exception waives only the RODS / ELD recordkeeping requirement; it does not waive the underlying HOS limits. A short-haul driver who exceeds the 14-hour window on a given duty period is no longer in the exception for that day and becomes required to keep a RODS for that day — not retroactively for earlier exception days.
8 · Agricultural
The 150 air-mile source-boundary exception
Under § 395.1(k)(1), the entire HOS rule set is suspended during planting and harvesting periods when a driver is transporting agricultural commodities within a 150 air-mile radius of the source of the commodity. The clock starts only when the driver crosses the 150-mile boundary; inside the boundary, the rules do not apply.
- “Agricultural commodities” is defined at § 395.2 and covers livestock, bees, horticultural products, hay, and the FMCSA's enumerated plant-and-animal products. The agency has issued specific guidance on the commodity scope including the 2018 clarification that aquatic animals and forest products fall within the definition.
- “Source” is the location from which the commodity is being loaded for transport — the farm gate, the feedlot, the orchard. The 150-mile radius is measured from that point.
- “Planting and harvesting periods” are designated by each state for each commodity. The FMCSA maintains a state-by-state list via its regulatory guidance archive; the periods overlap significantly across the year, so the practical effect is something approximating a year-round exception for many commodities.
Why this exception exists, and what's still contested
The agricultural commodity exception is a long-standing carve-out that the agriculture industry has fought to preserve and expand. Critics (including FMCSA's own staff in historical rulemaking comments) have argued that the 150-mile radius is large enough to cover most short-haul agricultural moves and that the planting-and-harvesting-periods framing is broad enough to effectively year-round-exempt some commodities. The 2018 clarification on aquatic and forest products expanded the scope further. Supporters argue the exception is necessary to handle the time-sensitive logistics of perishable commodity transport. The page does not take a position; the exception is what the regulation currently says.
9 · Adverse conditions
The 2-hour extension
Under § 395.1(b)(1), a driver who encounters adverse driving conditions that could not have been known about at the start of the duty period may extend the 11-hour driving limit by up to 2 hours and the 14-hour driving window by up to 2 hours to safely complete the run. The two-hour extensions apply independently and to the same shift; the driver does not get to use the time twice.
“Adverse driving conditions” under § 395.2 means snow, ice, sleet, fog, or other adverse weather conditions, or unusual road or traffic conditions, none of which the driver or the carrier could have foreseen at the time the run started. A forecasted storm the driver knew about at dispatch does not qualify. The burden of proof is on the driver to document the conditions (typically on the ELD's annotation field or a paper note on the RODS).
Before vs. after 2020
Prior to September 29, 2020, the adverse-conditions exception extended only the 11-hour driving limit, not the 14-hour window. A driver stopped by unexpected weather often had hours of driving available on the 11-hour clock but no window left in which to use them — an outcome the 2020 reform explicitly addressed. The new rule extends both clocks in parallel, so the driver can actually use the additional hours.
10 · Other exceptions and special cases
The smaller carve-outs
Beyond the four big accommodations (sleeper berth, short-haul, agricultural, adverse), a handful of smaller exceptions and special cases are worth naming. None gets its own section because each is narrow, but together they cover meaningful slices of the regulated driver population.
Emergency declarations
Under § 390.23, FMCSA can suspend HOS rules entirely for drivers providing direct assistance during a declared emergency. The COVID-19 emergency declaration (March 2020 through May 2022) is the longest-running precedent; hurricane and wildfire emergency declarations are issued routinely for shorter windows.
Oilfield operations
Under § 395.1(d)(2), drivers of specialized oilfield-servicing vehicles may use waiting time at a well site as a partial 10-hour-off-duty reset (the waiting time counts toward off-duty even though the driver is at the well site).
Construction-materials short-haul
Under § 395.1(q), drivers transporting construction materials and equipment have a 24-hour-restart option (instead of the standard 34) within a 75-air-mile radius of the work-reporting location.
16-hour exception
Under § 395.1(o), a non-CDL short-haul driver who normally returns to the work-reporting location may extend the 14-hour window to 16 hours once in any 7-day period. The exception is narrow and tracked closely by enforcement.
Passenger-carrying drivers
Drivers of CMVs designed to carry passengers (buses) operate under a parallel-but-different ruleset at § 395.5: 10-hour driving limit (vs. 11), 15-hour on-duty limit (vs. 14), no 30-minute break requirement, 8/2 sleeper-berth split only (no 7/3). This page focuses on the property-carrying ruleset; the passenger-carrying ruleset is out of scope here.
State-level intrastate operations follow each state's own HOS rules — most states adopt the federal ruleset by reference, but several (California's CCR Title 13, Texas's intrastate ag-hauler waivers, others) maintain divergences. The federal rules above cover interstate operations; intrastate is a state-by-state regime this page does not enumerate.
Sources
Primary sources
Everything on this page is sourced from federal primary records. The codified rule, the Federal Register rulemaking history, and the FMCSA's own guidance are public-domain federal works. I keep the citations inline so a broken link still leaves the source legible.
Codified rule (49 CFR)
- eCFR — 49 CFR Part 395 (Hours of Service of Drivers)
- eCFR — § 395.1 (Scope of rules in this part)
- eCFR — § 395.2 (Definitions)
- eCFR — § 395.3 (Maximum driving time for property-carrying vehicles)
- eCFR — § 395.5 (Maximum driving time for passenger-carrying vehicles)
- eCFR — § 395.8 (Driver's record of duty status)
Rulemaking history
- Federal Register — HOS-2020 final rule (effective September 29, 2020)
- Federal Register — HOS 2011 final rule (post-OOIDA v. FMCSA remand)
- Federal Register — HOS 2003 final rule
FMCSA guidance
- FMCSA — Summary of Hours of Service Regulations
- FMCSA — Interstate Truck Driver's Guide to Hours of Service
- FMCSA — Hours of Service Final Rule landing page (2020 reform hub)
- FMCSA — HOS-2020 FAQs
- FMCSA — “Agricultural Commodity” Exception, 49 CFR 395.1(k)(1)
- FMCSA — Personal Conveyance Regulatory Guidance
- FMCSA — Hours of Service regulatory-guidance archive
I keep this page narrowly bounded to the federal hours-of-service rules under 49 CFR Part 395 Subpart A for property-carrying CMVs. The recording-and-enforcement layer (Electronic Logging Devices, under Subpart B) is the sibling page at /trucking/eld/. The passenger-carrying ruleset (§ 395.5), state intrastate divergences, and the adjacent regulatory regimes (CDL licensing, drug-and-alcohol testing, hazmat, vehicle inspection, driver qualification) are out of scope here. Verify everything before acting on it — the primary sources above are authoritative; this page is a guide to them.