Hours of service rules, and whether the driver makes the appointment.
A driver's ETA is only as good as the hours behind it. Put in where the truck is, how much of today's clock is used, and the appointment, and the calculator applies the 11-hour, 14-hour and 30-minute rules to say when the truck can legally arrive. The rules themselves are underneath, in dispatcher terms.
- 11-hour driving limit
- A driver may drive at most 11 hours after 10 consecutive hours off duty.
- SoAbout 550 highway miles on a full clock; less after any wait.
- 14-hour window
- All driving must fall inside a 14-hour window that starts when the driver comes on duty. Off-duty time during the day does not extend it.
- SoFour hours at a dock are four hours of the window gone, even though no driving happened.
- 30-minute break
- After 8 cumulative hours of driving, a 30-minute break from driving (off duty, sleeper, or on duty not driving) before driving again.
- SoA long day always contains one; a load that will take 9 driving hours takes at least 9.5.
- 60/70-hour limit
- No driving after 60 hours on duty in 7 consecutive days (carriers not operating every day) or 70 hours in 8 days. A 34-hour off-duty period restarts the count.
- SoA driver at the end of a hard week may have a full daily clock and no weekly hours; ask.
- 10 hours off
- The daily reset: 10 consecutive hours off duty (or in the sleeper berth) before the next 11 and 14 begin.
- SoA truck 700 miles out at noon delivers tomorrow, after a 10-hour break somewhere in between.
- Sleeper berth split
- The 10 hours off can be split into two periods of at least 7 and at least 3 hours (7/3 or 8/2), one of them in the sleeper berth; neither counts against the 14-hour window.
- SoHow an experienced driver waits out a dock or a receiver that opens at 6 a.m. without losing the whole day.
- Adverse driving conditions
- Unexpected weather or road conditions not known at dispatch allow 2 extra hours of driving and window.
- SoSnow that was in the forecast does not qualify; a crash that closed the interstate does.
- Short-haul exception
- Drivers who stay within a 150 air-mile radius and return to the same location within 14 hours are exempt from logging and the 30-minute break.
- SoLocal and regional carriers; mostly irrelevant to over-the-road brokered freight.
- 16-hour exception
- Once every 7 days, a property-carrying driver who returns to the normal work reporting location may extend the window to 16 hours (not the driving limit).
- SoA tool for local fleets, not for an owner-operator crossing three states.
Why ETAs from drivers miss
A driver 400 miles from the receiver at 4 p.m. with three driving hours left arrives tomorrow morning, not tonight, and an ETA that says 11 p.m. was wrong before it was written down. Drivers know this and answer "first thing tomorrow"; shippers' portals want a time. The calculator above does the conversion: drive what the clock allows, take the ten hours, drive the rest, add the buffer for fuel and the dock, and compare with the appointment window.
Two things it cannot know. Whether the driver has hours on the weekly cycle (ask), and whether the 30-minute break has already been taken (ask). Both questions belong in every check call, and a tracking tool that records the answer next to the location is worth more than one that records the location alone. More on that in the guide on automating check calls, and on the terms in the glossary entries for hours of service, ETA and transit time.
FAQ
Questions about hours of service.
How many hours can a truck driver drive in a day?
Eleven hours of driving, inside a 14-hour on-duty window, after ten consecutive hours off duty, with a 30-minute break once eight hours of driving have accumulated. At highway speeds that is roughly 500 to 600 miles, which is why planners use 500 miles per day for a single driver.
Does waiting at a dock count against hours of service?
It counts against the 14-hour window unless the driver is properly off duty or in the sleeper berth, and it never gives driving hours back. A driver who arrived with eight driving hours left and waited four hours at the shipper still has eight driving hours but only six hours of window, so can drive six. That is the arithmetic behind detention charges.
What is the 34-hour restart?
Thirty-four consecutive hours off duty resets the 60-hour/7-day or 70-hour/8-day count to zero. A driver who has used 68 of 70 hours cannot legally take a 600-mile load tomorrow without one, whatever the daily clock says.
Can a dispatcher see a driver's remaining hours?
The carrier's dispatcher can, from the ELD. A broker cannot, unless the carrier shares it or the driver says. On the phone the question is "how many hours do you have left today and on your cycle," and the answer decides whether a delivery promise is real.
Are the hours of service rules changing?
The core limits have been stable since the 2020 revisions (the 30-minute break flexibility, the 7/3 sleeper split, the 150-air-mile short-haul radius, the adverse-conditions extension). Proposals surface regularly; check the FMCSA summary before relying on an exception you have not used before.