Where Your 14-Hour Window Actually Restarts After a Split
This is the part that generates more violations than any other piece of the rule. The regulation says it plainly, so let's do it plainly.
The sentence that matters
49 CFR 395.1(g)(1)(iii): once you've used two qualifying periods, both the 11-hour driving limit and the 14-hour window are recalculated from the end of the FIRST of the two periods — and the qualifying periods themselves don't count against the recalculated window.
Three consequences fall out of that one sentence:
- The work you did before your first break does not count against the new window. It counted against the original window, which the recalculation replaces.
- Everything you work between the two breaks does count against the new window. The breaks don't; the work does.
- Driving time is never excluded. Every driving hour — before, between, after — counts against 11. A split buys you window, never wheel time.
The deadline formula
Your driving must end by:
end of 1st break + 14 h + length of 2nd break
The second break pushes the deadline later by its own length because it isn't counted. From the moment your second break ends, your remaining window is simply 14 minus the on-duty hours you logged between the two breaks.
Worked example — short break first
6:00 AM on duty · 5 h driving + 1 h on-duty · 12:00–3:00 PM off duty (1st break) · 5 h driving · 8:00 PM–3:00 AM sleeper berth (2nd break)
Recalculation anchors at 3:00 PM. On-duty between the breaks: 5 h. Window left at 3:00 AM: 9 h — you may operate until 3:00 PM + 14 h + 7 h = 12:00 noon next day.
Driving: 5 + 5 = 10 of 11 used → 1 h of driving left. One hour up the road, then a full 10-hour reset — no third bite at the apple.
Worked example — long break first
7:00 AM on duty · 2 h driving · 9:00 AM–4:00 PM sleeper berth (1st break) · 3 h driving + 1 h at the receiver · 8:00–11:00 PM off duty (2nd break)
Anchor at 4:00 PM. On-duty between: 4 h → window left at 11:00 PM: 10 h, deadline 4:00 PM + 14 + 3 = 7:00 AM next day. Driving: 2 + 3 = 5 used → 6 h left.
Why "why didn't my 14 reset" keeps happening
- Nothing is excluded until the second break is complete. Mid-split, your ELD still shows the original window burning down. Drivers panic at hour 13, never finish the pairing, and the split evaporates.
- It's a recalculation, not a reset. You don't get a fresh 14 from the end of the second break — you get 14 minus the work between the breaks.
- Failed splits count both breaks back in. If inspection finds your "7-hour berth period" was 6.5, the window reverts to its original start — which often surfaces a secondary 14-hour violation you didn't know you were skating on.
If the split fails, both breaks count as ordinary off-duty and your original 14-hour window stands unchanged. The
calculator shows you that fallback window alongside the split math, so you can see exactly what you'd be left holding.