Hours of Service (HOS) Rules

Understanding Hours of Service (HOS) Regulations

Hours of Service (HOS) regulations are among the most important—and most complex—rules governing commercial trucking. These federal regulations dictate how long drivers can work and drive, and how much rest they must take. For dispatchers, mastering HOS is essential for legal compliance, driver safety, and operational efficiency.

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Why HOS Regulations Exist

Purpose:

Primary Goal:

• Prevent driver fatigue - Fatigue is a leading cause of truck crashes
• Improve highway safety - Well-rested drivers = safer roads
• Protect drivers - Prevent exploitation and exhaustion

Statistics:

• Fatigued driving contributes to 13% of large truck crashes
• HOS violations are among the most common FMCSA citations
• Proper rest reduces crash risk by 30-50%

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The HOS Rules: Complete Breakdown

1. 11-Hour Driving Limit

Rule:

• May drive a maximum of 11 hours after 10 consecutive hours off duty

Explanation:

• Driver must be off duty (or in sleeper berth) for at least 10 straight hours
• After that 10-hour break, driver can drive up to 11 hours
• Driving time can be split throughout the 14-hour window

Example:

• Driver goes off duty at 10 PM
• Gets 10 hours rest
• Comes on duty at 8 AM
• Can drive up to 11 hours (until 7 PM if driving straight)
• But limited by 14-hour window (see next rule)

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2. 14-Hour On-Duty Limit (14-Hour Window)

Rule:

• May not drive beyond the 14th consecutive hour after coming on duty, following 10 consecutive hours off duty

Explanation:

• 14-hour "window" starts when driver comes on duty
• All time counts: driving, loading, fueling, inspections, waiting
• Cannot be extended by off-duty time during the 14 hours
• After 14th hour, driver cannot drive until taking 10-hour break

Critical Point:

• The 14-hour clock does NOT stop
• If driver takes 2-hour break for lunch (off duty), the clock keeps ticking
• After 14 hours from start, no more driving allowed

Example:

• Driver starts on duty at 6 AM (14-hour window begins)
• 6 AM - 10 AM: Drives 4 hours
• 10 AM - 12 PM: Off duty (lunch) - 14-hour clock still running
• 12 PM - 6 PM: Drives 6 hours
• 6 PM - 8 PM: At customer, on duty not driving - 14-hour clock still running
• 8 PM: Reaches 14th hour - CANNOT DRIVE even though only drove 10 hours
• Must take 10-hour break before driving again

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3. 30-Minute Break Rule

Rule:

• Driving is not permitted if more than 8 cumulative hours have passed since the end of the driver's last off-duty or sleeper-berth period of at least 30 minutes

Simplified:

• After driving 8 hours total, must take 30-minute break
• Break must be off duty or in sleeper berth
• "On duty not driving" does NOT count as break

2020 Change:

• Break can now be satisfied by on-duty not driving (e.g., loading, unloading)
• More flexibility for drivers

Example:

• Driver starts driving at 6 AM
• Drives from 6 AM - 2 PM (8 hours cumulative)
• Must take 30-minute break before continuing to drive
• Break from 2 PM - 2:30 PM
• Can resume driving at 2:30 PM

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4. 60/70-Hour Limit (Weekly Limit)

Rule:

• May not drive after being on duty for:
  • 60 hours in 7 consecutive days, OR
  • 70 hours in 8 consecutive days

Which One Applies:

• 7-day limit (60 hours): For carriers that do not operate commercial vehicles every day of the week
• 8-day limit (70 hours): For carriers that do operate commercial vehicles every day of the week

Calculation:

• Rolling total of previous 7 or 8 days
• Includes all on-duty time (driving and non-driving)

Example (70-hour/8-day):

• Driver worked 70 hours total in past 8 days
• Cannot drive until hours "fall off" the 8-day window
• OR takes a 34-hour restart (see below)

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5. 34-Hour Restart

Rule:

• A driver may restart the 7/8-day period after taking at least 34 consecutive hours off duty

Purpose:

• Allows driver to "reset" the 60/70-hour clock
• Returns to 0 hours for 7/8-day calculation

How It Works:

• Driver accumulates 68 hours in 8 days
• Takes 34 consecutive hours off duty
• 60/70-hour clock resets to 0
• Can work full weeks again

Example:

• Driver works Monday-Friday, accumulates 60 hours
• Goes off duty Friday at 6 PM
• Stays off duty until Sunday at 4 PM (34 hours)
• Clock resets to 0 hours
• Can start fresh on Monday

2020 Simplification:

• Old rule required restart to include two 1 AM - 5 AM periods
• Current rule: Simply 34 consecutive hours off duty (no time-of-day requirement)

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Sleeper Berth Provision

Split Sleeper Berth Rule:

Purpose:

• Allows drivers to split required 10-hour off-duty time
• Provides flexibility for team drivers or difficult schedules

How It Works:

• Driver can split 10-hour break into:
  • 8 hours in sleeper berth, AND
  • 2 hours either off duty, in sleeper berth, or any combination
• Neither period counts against 14-hour window
• Driving time is calculated from end of longer rest period

Requirements:

• Minimum 8-hour sleeper berth period
• Minimum 2-hour off-duty/sleeper period (can be longer)
• Both periods must add up to at least 10 hours

Example:

• Driver takes 8-hour sleeper berth break
• Drives for some hours
• Takes 2-hour off-duty break
• This equals 10-hour break split
• 14-hour clock calculated from end of 8-hour break

2020 Change:

• Split can now be 7/3 (7 hours sleeper + 3 hours off-duty) instead of just 8/2
• More flexibility

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Driver Classifications and Mileage

Solo Driver:

Definition:

• One driver operating the truck

Legal Daily Mileage:

• Up to 600 miles per day (legal average)

Calculation:

• 11 hours driving × ~50-55 mph average (accounting for stops, traffic, fuel) = ~550-600 miles

Realistic:

• Most dispatchers plan 500-550 miles/day for solo drivers
• Accounts for loading/unloading, traffic, weather

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Team Drivers:

Definition:

• Two drivers alternating shifts in same truck
• One drives while other rests in sleeper berth

Legal Daily Mileage:

• Up to 1,200 miles per day (legal average)

How It Works:

• Driver A drives 11 hours, goes to sleeper berth
• Driver B takes over, drives 11 hours
• Truck operates nearly 24/7
• Double the daily miles

Sleeper Berth Use:

• Each driver must still comply with HOS individually
• While one drives, other must be in sleeper berth
• Each driver logs their own hours

Benefits:

• Faster transit times - Cross-country in 2-3 days instead of 5
• Higher revenue - More miles covered
• Premium rates - Expedited freight pays more

Challenges:

• Finding compatible team partners
• Living in tight space with another person
• Sleep quality - Sleeping while truck moving
• Coordination

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On-Duty vs. Off-Duty Status

Duty Status Categories:

1. Off Duty:

• Not working
• Not under dispatcher's control
• Free to do as driver pleases
• Examples: Home time, hotel, personal errands

2. Sleeper Berth:

• Resting in truck's sleeper compartment
• Can be used for required rest periods
• Examples: Sleeping in truck

3. Driving:

• Operating the commercial motor vehicle
• Automatically recorded by ELD

4. On-Duty Not Driving:

• Working but not driving
• Examples:
  • Pre-trip/post-trip inspections
  • Loading/unloading (if driver helps)
  • Fueling
  • Waiting at customer (unless released)
  • Paperwork
  • Vehicle maintenance

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Gray Areas - On Duty or Off Duty?

Waiting at Shipper/Receiver:

• If required to stay = On Duty Not Driving
• If released and free to leave = Off Duty (rare)

Meal Breaks:

• If driver is free from work = Off Duty
• If required to stay with truck or monitor = On Duty Not Driving

Riding in Passenger Seat (Team):

• If actively monitoring co-driver = On Duty Not Driving
• If sleeping/resting with co-driver driving = Sleeper Berth

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Mandatory Rest Periods

10-Hour Break Requirement:

When Required:

• After driving 11 hours (max driving time)
• After 14 hours on duty (end of window)
• Before starting a new shift

Must Be:

• 10 consecutive hours
• Off duty or in sleeper berth
• Cannot be interrupted by on-duty time

Exception:

• Sleeper berth split (8/2 or 7/3)

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34-Hour Restart:

When Used:

• To reset 60/70-hour weekly limit
• Typically used for weekend rest

Requirements:

• 34 consecutive hours off duty
• After completion, 60/70-hour clock resets to 0

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Short-Haul Exception (100 Air-Mile Radius)

Who Qualifies:

Requirements:

• Operates within 100 air-mile radius of work reporting location
• Returns to work reporting location every day
• Driver is released from duty within 12 consecutive hours

Benefits:

• No ELD required (can use time cards)
• No logbook required
• 14-hour window extended to 12-hour on-duty limit

Common Users:

• Local delivery drivers
• Construction trucking (dump trucks, concrete)
• Short-haul regional carriers

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150 Air-Mile Exemption (CDL Drivers):

Similar to 100 air-mile but:

• 150 air-mile radius
• Still no ELD if within 12 hours
• Must maintain time records

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Adverse Driving Conditions Exception

What It Is:

Allows:

• Extension of 11-hour driving time and 14-hour on-duty limit by up to 2 hours

When It Applies:

• Adverse driving conditions that were not known to driver at start of shift
• Driver cannot safely complete trip within normal HOS limits due to unforeseen conditions

Examples:

• Unexpected snow/ice storm
• Unexpected severe traffic (accident-related)
• Road closures due to unforeseen events

Does NOT Apply:

• Normal rush hour traffic (foreseeable)
• Weather forecasted before shift started
• Construction (if known beforehand)

How It Works:

• Driver can drive up to 13 hours (instead of 11)
• 14-hour window extends to 16 hours
• Must be noted in ELD/logbook with explanation

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Emergency Exception

When It Applies:

Definition:

• True emergencies requiring immediate response
• HOS rules temporarily suspended

Examples:

• Natural disasters (hurricanes, floods, wildfires)
• Pandemic response (COVID-19 medical supplies)
• Public health emergencies

Declaration:

• Usually declared by federal or state government
• FMCSA issues emergency declaration
• Specific to certain types of freight/regions

Duration:

• Typically limited (30 days, extendable)

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HOS Violations: Common Mistakes

Top HOS Violations:

1. Driving Over 11 Hours:

• Penalty: $1,000-$11,000
• Driver: Out-of-service until 10-hour break completed
• CSA Points: Severe

2. 14-Hour Window Violation:

• Driving after 14th hour
• Penalty: Same as above
• Common mistake: Thinking off-duty time extends window (it doesn't!)

3. No 30-Minute Break:

• Driving past 8 hours without break
• Penalty: $1,000-$5,000
• CSA Points: Moderate

4. 60/70-Hour Violation:

• Exceeding weekly limit
• Penalty: $1,000-$11,000
• Driver: Out-of-service

5. Logbook Falsification:

• False entries in ELD or paper log
• Penalty: $1,000-$11,000
• Criminal charges possible
• CSA Points: Severe

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Dispatcher's HOS Responsibilities

Before Dispatching Load:

Check Driver Availability:

1. ✅ Hours remaining today - Can driver complete pickup/delivery?
2. ✅ Weekly hours - Approaching 60/70 limit?
3. ✅ Current status - Driving, on-duty, off-duty, sleeper?
4. ✅ Next break due - When does 30-minute break needed?
5. ✅ 14-hour window - When does it expire?

Calculate Transit Time:

1. ✅ Miles ÷ 50 mph = Driving hours needed
2. ✅ Add time for loading, unloading, breaks, fuel
3. ✅ Verify driver has enough hours available
4. ✅ Build buffer - Don't use every available hour

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Never Pressure Drivers:

Illegal and Dangerous:

• ❌ NEVER ask driver to violate HOS
• ❌ NEVER suggest "creative logging"
• ❌ NEVER pressure driver to skip breaks
• ❌ NEVER ignore driver reporting low hours

Coercion Rules:

• FMCSA prohibits carriers from coercing drivers to violate regulations
• Penalties: $16,000+ per violation
• Carrier liability if dispatcher pressures driver

Right Approach:

• ✅ Plan loads that comply with HOS
• ✅ Respect driver's hours
• ✅ Build realistic schedules
• ✅ Have backup plan if delays occur

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HOS Planning Tools:

Software:

• ELD systems (KeepTruckin, Samsara, Omnitracs)
• TMS with HOS integration
• Route planning with HOS calculations

Manual Calculation:

• Trip miles ÷ 50 mph = Driving hours
• Add 2-3 hours for non-driving activities
• Compare to driver's available hours
• Plan breaks every 8 hours

Example Calculation:

• Load: 500 miles
• Pickup time: 2 hours
• Delivery time: 1 hour
• Fuel stop: 0.5 hour
• Total: 500 mi ÷ 50 = 10 hrs driving + 3.5 hrs other = 13.5 hours total
• Driver needs 13.5 hours within 14-hour window - Tight but doable
• Driver must have at least 11 hours driving available

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ELD and HOS Compliance

Electronic Logging Devices:

Automatic Recording:

• ELD automatically records:
  • Driving time (via engine data)
  • Engine hours
  • Vehicle movement
  • Miles driven
  • Location

Driver Input:

• Driver selects duty status:
  • Off Duty
  • Sleeper Berth
  • Driving (auto-detected)
  • On-Duty Not Driving

Edits:

• Driver can edit certain entries
• System records all edits
• Cannot delete history

Dispatcher Access:

• Real-time HOS monitoring
• Available hours display
• Violation alerts
• Reports

(Detailed coverage in Understanding ELDs article)

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Conclusion

Hours of Service regulations are designed to keep drivers safe and well-rested. Compliance requires understanding the rules, careful planning, and respect for drivers' limits.

Key Takeaways:

The Rules:

• ✅ 11-hour driving limit after 10 hours off
• ✅ 14-hour on-duty window (does not pause)
• ✅ 30-minute break after 8 hours driving
• ✅ 60/70-hour weekly limit
• ✅ 34-hour restart to reset weekly clock

Driver Limits:

• Solo driver: ~500-600 miles/day
• Team drivers: ~1,000-1,200 miles/day

Dispatcher Must:

• ✅ Verify driver hours before dispatch
• ✅ Plan realistic schedules
• ✅ Never pressure drivers to violate HOS
• ✅ Monitor HOS compliance continuously
• ✅ Address violations immediately

"HOS compliance isn't about maximizing every available hour—it's about planning smart, keeping drivers safe, and building sustainable operations."

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Continue Learning:

• FMCSA Regulations
• Understanding ELDs
• DOT Compliance

Master HOS rules to dispatch legally and safely. Continue your education at Carriversity.