What are Hours of Service (HOS)?

The Hours of Service final rule went into effect in December 2011 as a way for the Federal Motor Carrier Safety Administration (FMCSA) to monitor working hours of anyone operating a commercial motor vehicle or a CMV with a CDL in the United States. A CMV refers to any vehicle that is used as part of a business that operates in interstate commerce. Designed to eliminate accidents caused by driver fatigue, the ruling determines the maximum number of consecutive hours a commercial truck driver or other types of CMV operators can drive or work before taking a mandatory rest break.

Under the ELD mandate, a US regulation that went into effect in December 2017, operators of commercial motor vehicles are required to use electronic logging devices to track Hours of Service (HOS). Electronic logging devices, also known as electronic logbooks or e-logs, connect to a vehicle's engine and automatically record driving time, providing a reliable way to collect HOS data. They replace paper logs which were historically used in the trucking industry to record Hours of Service.

Anyone found to be in violation of the Hours of Service rules runs the risk of negatively impacting their carrier's safety rating or even being put out of service for a certain period of time.



What is the driving limit for CMV drivers?

The Hours of Service regulation limits the number of driving hours per day and the number of driving and working on-duty hours per week. Driving limit or cycle limit restrictions include:

14-hour shift limit

Drivers have a 14-hour window to drive a maximum of 11 hours and are required to take a 30-minute break every 8 hours. The 14-hour driving limit restricts drivers from driving any longer than the fourteenth consecutive hour on duty, after 10 hours off duty.

11-hour driving limit

A driver is limited to a maximum of 11 hours of driving after 10 consecutive hours off duty.

60/70-hour limit

The HOS rules cap driving time to 60 hours per 7-day period and a 70-hour time limit for a span of 8 days. This means drivers cannot continue to drive once they've reached 60/70 hours of on-duty time in 7/8 consecutive days.

34-hour restart

The 34-hour restart rule gives commercial motor vehicle drivers the opportunity to reset their 60-hour or 70-hour clocks back to zero. Drivers can take advantage of the rule at any time by taking at least 34 consecutive hours off duty or in a sleeper berth.



Rest breaks

Drivers are required to take a 30-minute rest break after continuously driving for 8 hours. Rest breaks can be logged as either off-duty time or can be taken as time in the sleeper berth at a truck stop or other rest area.

Sleeper berth ruling

A sleeper berth refers to a cab in the back of a truck that includes a reclining seat or bed that drivers can use for rest while they're on the road. Drivers can use the time spent in the sleeper berth to count towards their mandatory rest-limits or their off-duty time.

The driver can spend 10 consecutive hours of off-duty time in their sleeper berth to meet rest-break requirements or extend a 14-hour on-duty period if they’re using the split sleeper rule. Furthermore, a driver can use the ‘split sleeper berth provision’ to split their time, as long as they spend a total of at least 8 hours in the sleeper berth and if each of the two work periods lasts at least 2 hours.

Who is subject to Hours of Service rules?

The Hours of Service regulation applies to any commercial motor vehicle operator in the United States. A commercial motor vehicle, outside of belonging to a company or corporation, is defined as any vehicle that satisfies one of the following conditions:

  • Weighs (including any load) 10,001 lbs or more
  • Transports hazardous materials (property-carrying vehicle) in a quantity requiring a hazardous material placard
  • Transports 16 or more passengers (passenger-carrying vehicle), including the driver, without compensation
  • Transports 9 or more passengers (passenger-carrying vehicle), including the driver, for compensation


How to avoid Hours of Service penalties

HOS regulations are strictly enforced by the Department of Transportation (DOT), but there are a number of ways to satisfy the ruling's requirements and even certain instances when a driver is exempt.

100 air-mile short-haul exemption

Under the 100 air-mile short-haul exemption, the 14-hour driving window is extended to 16 hours. Any driver who falls within a 100 air-mile driving radius can extend one 14-hour driving window per week to a 16-hour shift.

Electronic logging device (ELD) solutions

The best way to prevent Hours of Service violations is to use an ELD compliance solution.

Samsara's electronic logging device is an FMCSA-approved ELD that connects to the engine's OBD port and automatically collects vehicle data throughout the day. This, combined with the HOS electronic log book in the Samsara driver app, provides fleets with an accurate and complete read of their compliance. Whether you're an owner-operator or a fleet manager, Samsara can help your business gain visibility into your driver's hours of service.

Through the Samsara dashboard, compliance managers can review the Hours of Service report to see drivers' real-time driving status, the amount of time until their rest break, and the number of hours left in their driving period. This report will automatically flag any driver approaching an Hours of Service violation.

To keep your fleet compliant and avoid ELD violations, it's important to stay up to date on current ELD news and announcements. To help, we've compiled the latest news to keep you informed on the most recent ELD insights in the trucking industry.



Learn more about Samsara's ELD compliance solution