Hours of Service

What is the 14-Hour Rule?

The 14-hour rule is a federal safety Hours of Service rule that applies to commercial motor vehicle (CMV) drivers.  

This post explains the details of this rule, and why it is commonly referred to as the “driving window.”

The 14-hour rule

The 14-hour rule can best be described as a property-carrying CMV driver’s ‘driving window.’  

A property-carrying CMV driver is allowed a period of 14 consecutive hours during each work shift (the driving window) in which to drive up to a maximum of 11 hours.

The 14-consecutive hour driving window starts when the driver begins any type of work (e.g., doing a pre-trip inspection of the truck and/or trailer at the beginning of the work shift).  

When a driver reaches the end of the 14-consecutive hour driving window, the driver may not drive until he/she has been off-duty for at least 10 consecutive hours.

What is the purpose of the 14-hour rule?

The purpose of this rule is to prevent drivers from driving while they may be suffering from fatigue after a long day.  

The longer we, as humans, are awake and working, the less alert we become. Fatigue scientists call this “acute” fatigue.

Is non-driving work allowed at the end of the 14-hour driving window?

Yes, a driver is allowed to perform non-driving work at the end of the 14-consecutive hour driving window.

For example, a driver could stay on-duty to complete paperwork, perform a post-trip vehicle inspection, etc.  Only driving a CMV in commerce is prohibited at the end of the 14-consecutive hour driving window.

Can the 14-hour driving window be paused?

Generally speaking, the 14-consecutive hour driving window cannot be paused.  

In addition to it being called the driving window, the 14 consecutive hours is often referred to as a driver’s ‘running clock’.  Even if a driver takes some off-duty time for a meal or a coffee break during the work shift, that break does not pause or stop the 14-consecutive hour driving window (the running clock).

Note:  If a driver is operating a truck with a sleeper berth, rest periods taken in the sleeper berth during a work shift may pause the 14-consecutive hour driving window.