Driver Fitness, Hours of Service, and Fatigue
What this domain tests
This domain covers the hours-of-service limits for property-carrying CMV drivers and the fitness issues that cause fatigue. Questions focus on the 11-hour and 14-hour rules, the 30-minute break, and reset periods.
Core rules
- Drive no more than 11 hours after 10 consecutive hours off duty.
- Do not drive beyond the 14th consecutive hour after coming on duty; the 14-hour window is not extended by breaks.
- Take a 30-minute break after 8 cumulative hours of driving.
- Follow the 60-hour/7-day or 70-hour/8-day limit, and use a 34-hour restart when eligible.
- Fatigue impairs judgment like alcohol. Rest, meal timing, and sleep habits matter more than caffeine.
Worked example
A driver starts at 06:00, drives 4 hours, performs 2 hours of on-duty non-driving work, then drives 4 more hours. At 16:00 the driver has 8 driving hours and must take a 30-minute break before driving again. The 14-hour window ends at 20:00, so the break and loading time count against it.
Traps
Treating the 30-minute break as off-duty, assuming breaks extend the 14-hour window, and counting loading time as off-duty are common errors.