Abbreviation: HOS
Hours of Service
Federal rules in 49 CFR Part 395 limiting how long a CDL driver may drive and remain on duty in a given day or week.
Key property-carrier limits: 11-hour driving limit after 10 consecutive hours off duty; 14-hour on-duty window; 30-minute break after 8 hours of driving; 60/70-hour weekly limit. The 34-hour restart provision allows resetting the weekly counter. ELDs enforce these limits automatically.
Property carrier daily limits
Property-carrying CMV drivers may drive up to 11 hours after 10 consecutive hours off duty. All driving and on-duty time must occur within a 14-hour window that begins when the driver comes on duty after the rest period. Driving is not permitted after the 14-hour window closes, even if the driver hasn't used all 11 hours. A 30-minute break is required before the 8th hour of driving.
Weekly on-duty limits
Drivers operating on a 7-day week may not exceed 60 total on-duty hours. Drivers operating on an 8-day week may not exceed 70 hours. The weekly counter cannot be exceeded regardless of daily hours. The 34-hour restart allows resetting this counter by taking 34 or more consecutive off-duty hours.
Passenger carrier differences
Passenger-carrying CMV drivers operate under separate HOS rules: a 10-hour driving limit (vs. 11), a 15-hour on-duty window (vs. 14), and an 8-hour rest requirement after 10 driving hours. The 30-minute break requirement applies differently. Passenger-carrier drivers must verify they are using the correct rule set for their vehicle type.
Last updated: May 28, 2026
When this definition matters
This term usually matters when a driver, owner-operator, or small carrier is deciding whether a federal rule applies, preparing a compliance file, or checking a state CDL step. Use this definition as a starting point, then confirm the controlling requirement in the official source listed below before making a licensing, hiring, dispatch, or recordkeeping decision.
The related terms above are included because they often appear in the same compliance workflow. Reviewing them together can prevent common mix-ups, such as treating a state licensing step as a federal carrier obligation or confusing a driver record with a separate employer record.