• Once a driver of a passenger-carrying CMV accumulates 15 hours of on-duty time (driving or non-driving work), there can be no more driving until the driver gets 8 hours off duty.
• A driver of a passenger-carrying CMV could work and drive beyond the 15th or even 20th consecutive hour of the day if the workday is extended with off-duty time.

The driver of a passenger-carrying commercial motor vehicle (CMV) operating in interstate commerce is prohibited from driving after having been on duty for 15 hours following 8 consecutive hours off duty. The 15-hour period is not consecutive; it includes only on-duty and driving time, not time spent off duty or in a sleeper berth. Once a driver accumulates 15 hours of on-duty time, there can be no more driving until the driver gets another 8 hours off.

The 15-hour rule is sometimes misunderstood to mean that a driver must be released from duty after 15 on-duty hours. However, the hours-of-service (HOS) rules only regulate driving, not working. A driver can do non-driving work beyond the 15-hour limit, just no more driving.

Federal definitions

The term driving time means all time spent at the controls of a CMV in operation.

The term on-duty time is defined in “What is on-duty and off-duty time?”

15-hour rule differs from the 14-hour rule for property-carrying CMVs

Keep in mind that this 15-hour rule for drivers of passenger-carrying CMVs is very different from the 14-hour rule for drivers of property-carrying CMVs. The 15-hour limit includes only “on-duty” time, the same time that goes into calculating the 60/70-hour limit. Off-duty and sleeper-berth time are never included in this calculation. This means a motorcoach driver, for example, could work and drive beyond the 15th or even 20th hour of the day if the workday is extended with off-duty time.

All time spent performing work, other than driving, must be logged as “on-duty/not driving” time (Line 4 on the grid). This time, together with driving time, makes up the total on-duty time.

Options for resetting the clock

Getting 8 hours off will reset the 15-hour limit. The same four options for obtaining 8 hours of rest to reset the 15-hour clock apply as they do for the 10-hour driving limit.

The 15-hour limit does not allow more than 10 hours of driving; it merely allows time to perform duties other than driving. Also, at the 15th hour the driver is not required to stop working but is required to stop driving. The violation is always one of driving after having attained the maximum permitted hours. Nothing stops a driver from continuing to work in an “on-duty/not driving” status.

Key points:

• The 15 hours are not consecutive. They include only time spent on duty or driving (lines 3 and 4 on a log). If the driver goes off duty for lunch or other breaks or takes a nap in a sleeper berth, that time does not count toward the 15-hour limit. This means a driver that has multiple off-duty breaks during the day may be able to drive well beyond the 15th consecutive hour from when driving began.
• 10 out of the 15 hours can be spent driving a CMV.
• The driver can do other work after 15 on-duty hours, but can’t do any more CMV driving until getting 8 hours off.
• A driver can exceed the 15-hour limit by up to 2 hours when encountering adverse driving conditions.

Example

Here is an example of the 15-hour rule in action:

This driver accumulated 15 on-duty hours (lines 3 and 4) by 8 p.m., including 10 hours of driving. The driver violated both rules by driving for an hour at 11 p.m. without first having another eight hours off. Note that the hour on duty after the 15-hour limit was reached (from 8-9 p.m.) was legal because it was not “driving.”