Lesson 1: The clocks, defined precisely

What you will be able to do after this lesson

• Define the four duty statuses and say which ones count against which clock.
• Track the 11-hour, 14-hour, 30-minute-break and 60/70-hour clocks at the same time.
• Work out, from a driver's day so far, exactly how many hours are left and when the window closes.
• Explain the 34-hour restart.

Scope: This course covers the federal rules for property-carrying drivers (49 CFR Part 395). Passenger carriers, some state intrastate rules and special operations differ. Confirm current rules with FMCSA before you rely on any detail.

1. The four duty statuses

Every minute of a driver's day is in one of four statuses.

Status	Meaning	Counts toward the 14-hour window?	Counts toward the 60/70-hour limit?
Driving	Operating the vehicle	Yes	Yes
On duty, not driving	Working but not driving: loading, unloading, inspections, fuelling, waiting at a dock if not relieved, paperwork	Yes	Yes
Sleeper berth	Resting in the truck's sleeper berth	Yes, unless it forms part of a qualifying split (Lesson 2)	No
Off duty	Relieved of all responsibility	Yes, unless it forms part of a qualifying split	No

Two points beginners miss:

1. Waiting is not automatically off duty. If the driver is told to stay with the truck or be ready to load, he is on duty. He is off duty only if he is relieved of all responsibility and free to leave.
2. The 14-hour window keeps running through breaks. Off-duty time in the middle of the day does not stop it, except in the sleeper-berth splits covered in Lesson 2.

2. The five rules at a glance

Rule	What it says
Reset	A driver needs 10 consecutive hours off duty (or sleeper, or a combination) before starting a new driving period.
11-hour driving limit	No more than 11 hours of driving after coming on duty following the 10-hour break.
14-hour window	No driving after the 14th consecutive hour after coming on duty following the 10-hour break.
30-minute break	A break of at least 30 consecutive minutes (non-driving) is required once 8 cumulative hours of driving have passed without one.
60/70-hour limit	No driving after 60 hours on duty in 7 consecutive days or 70 hours in 8 consecutive days, depending on the carrier's operating schedule.

Plus the 34-hour restart, which resets the 60/70-hour clock.

3. Clock by clock

The 11-hour clock

Counts driving time only. It accumulates across the shift, and stops only when the driver takes the 10-hour break. Stopping for lunch does not reset it.

The 14-hour clock

Starts when the driver comes on duty after a 10-hour break (the first on-duty minute, even if he is not driving). The window closes 14 hours later. After that, no driving, even if the driver has driven only 3 hours. Non-driving work such as unloading is still permitted after the window closes, but the driver cannot drive.

The 30-minute break clock

Starts counting after the last 30-minute non-driving interruption (or the start of the shift). When the driver reaches 8 cumulative hours of driving without a 30-minute interruption, the break must be taken before driving further. The break can be:

• Off duty,
• Sleeper berth, or
• On duty, not driving (for example, waiting at a dock or fuelling).

Nothing in the rule says "30 minutes after 8 hours on duty". It is 8 hours of driving, so short stops while driving do not count unless they total a 30-minute non-driving period.

The 60/70-hour clock

Counts all on-duty time (driving and not driving) over a rolling window:

• 60 hours in 7 days: for carriers that do not operate vehicles every day of the week.
• 70 hours in 8 days: for carriers that do operate every day of the week.

Rolling means the oldest day drops off the back each day. The driver's available hours each day are what is left after adding up the previous 7 or 8 days, including today.

The 34-hour restart

If the driver takes 34 or more consecutive hours off duty (off duty, sleeper, or a combination), the 60/70-hour total resets to zero. The older rule that required the restart to include two periods between 1 a.m. and 5 a.m. is no longer part of the current rule.

4. Worked examples

Example 1: all clocks together

A driver has had a full 10 hours off. He comes on duty at 5:30 a.m. (a 30-minute pre-trip), starts driving at 6:00 a.m. and drives until 11:00 a.m. (5 hours). He loads from 11:00 to 12:30 (on duty, not driving), and then drives from 12:30 to 3:30 p.m. (3 hours).

• Driving so far: 5 + 3 = 8 hours. 3 hours left on the 11-hour clock.
• 14-hour window: started 5:30 a.m., closes at 7:30 p.m.
• 30-minute break: he had a 90-minute on-duty-not-driving period (loading) after 5 hours of driving. That is a qualifying break (a non-driving interruption of 30+ minutes), so the 8-hour break clock restarted at 12:30. He has driven only 3 hours since, so no break is due yet.
• What he can still do: drive up to 3 more hours, and it must be completed before 7:30 p.m.

Example 2: when the window, not the driving, is the limit

A driver comes on duty at 7:00 a.m., waits at a shipper until 1:00 p.m. (on duty, not driving) and then drives.

• 14-hour window closes at 9:00 p.m.
• Time left to drive: 8 hours (1:00 p.m. to 9:00 p.m.), assuming he has driven nothing yet.
• Driving limit left: 11 hours, but only 8 hours fit in the window. He cannot reach 11. The window is the binding limit.
• Because the wait before driving was a non-driving period of more than 30 minutes, the break clock starts fresh at 1:00 p.m. He can drive 8 hours with no break, and a break is needed only to drive beyond that. In an 8-hour window that means he can use all 8 hours. If he took a 30-minute break to drive a little more, the break would use up window time too.

This example is why a 6-hour wait at a dock is so costly. It consumed a large part of the day's available driving without moving a mile.

Example 3: the 70-hour clock

A driver works for a carrier that operates seven days a week (70/8). Over the last 8 days (including today so far) his on-duty hours are: 10, 11, 9, 12, 11, 8, 10, 0 (today so far).

• Total = 10 + 11 + 9 + 12 + 11 + 8 + 10 = 71 hours. That already exceeds 70, so he cannot drive today. He needs a 34-hour restart or must wait until enough old hours drop off.

When does he get hours back? As each day falls off the back of the 8-day window. If tomorrow's window drops the first day (10 hours), his total falls to 61 hours, leaving 9 hours available.

Example 4: a 34-hour restart

A driver finishes his last load at 6:00 p.m. Friday and goes off duty. He becomes eligible for a restart at 4:00 a.m. Sunday (34 hours later). If he starts work before that, the restart does not count and his 60/70 total continues.

5. Putting it together: the "three limits" check

Before any trip, a dispatcher or driver should find the smallest of:

1. Hours left on the 11-hour clock.
2. Hours left in the 14-hour window.
3. Hours left on the 60/70-hour clock.

Then subtract the time needed for the 30-minute break if it is due. The smallest number is the real number of driving hours available, and the load must fit inside it, or fit with a legal rest in between.

6. The most common misunderstandings

1. "He's only driven 8 hours, so he's fine." He may be out of window.
2. "Waiting at the shipper doesn't count." It does, for the 14-hour window and for the 60/70.
3. "He took lunch, so the clock stopped." The 14-hour window kept running.
4. "The 30-minute break must be off duty." Not necessarily. On-duty-not-driving also counts.
5. "A short nap resets everything." Only 10 consecutive hours (or a qualifying split) resets the shift clocks.
6. "The 70-hour rule means 70 hours of driving." It counts all on-duty time.

Key terms

• Duty status: driving, on duty not driving, sleeper berth, off duty.
• 14-hour window: the period within which all driving must be completed.
• Cumulative driving: total driving since the last 30-minute break.
• Rolling 7/8-day: the moving window for the 60/70 limit.
• Restart: 34 consecutive hours off duty that resets the 60/70 clock.

Check your understanding

1. A driver comes on duty at 6:00 a.m. after a full 10 hours off, and waits at a dock until 11:00 a.m. before driving. When does his window close, and how many driving hours can he fit in?
2. List the three types of duty that qualify as the 30-minute break.
3. A driver on a 70/8 schedule has 62 hours on duty over the last 8 days. How many hours does he have left before the limit?
4. What resets the 60/70-hour clock?

Answers: (1) 8:00 p.m. closes the window, giving 9 hours between 11:00 a.m. and 8:00 p.m. (and he needs a 30-minute break, so about 8.5 driving hours). (2) Off duty, sleeper berth, and on duty not driving. (3) 8 hours. (4) 34 or more consecutive hours off duty.