Hours of Service (HOS) rules aren't optional guidelines. They're federal law under 49 CFR Part 395, and non-compliance carries real financial teeth. This guide breaks down the core limits, the exemptions fleets actually qualify for, the most common violations, and practical steps to stay ahead of them. We'll also touch on how GPS fleet tracking technology takes manual guesswork out of the equation.
Key Takeaways
- Property-carrying drivers may drive 11 hours inside a 14-hour window after 10 consecutive hours off duty
- 30-minute break required after 8 hours of driving; weekly on-duty caps are 60 hours/7 days or 70 hours/8 days
- HOS violations can trigger fines, out-of-service orders, and long-term CSA score damage
- Exemptions exist for short-haul routes, adverse driving conditions, and agricultural work
- 34-hour restart fully resets the weekly clock and can be used as often as needed
What Are Hours of Service Rules and Who Must Follow Them
HOS rules are FMCSA regulations designed to cap how long a commercial driver can drive or stay on duty before resting. The goal is simple: reduce fatigue-related crashes. Drivers have been required to log their hours since the 1930s, but today's rules are far more precise and far more enforceable, thanks to electronic logging devices (ELDs).
These rules apply to any commercial motor vehicle (CMV) that meets one of these criteria
- Weight: Gross vehicle weight or combined weight rating over 10,000 pounds
- Passengers: Transports 16+ people (including the driver), or 9+ for commercial purposes
- Hazmat: Carries materials that require placarding
Interstate vs. Intrastate Commerce
If a driver crosses state lines, federal HOS rules apply with no exceptions. Drivers who stay entirely within one state often fall under that state's own intrastate rules instead, which can differ meaningfully from the federal baseline.
There's one wrinkle worth flagging: a placarded hazmat exception. Any vehicle transporting placard-quantity hazardous materials must follow HOS rules regardless of whether the trip is interstate or intrastate. For that reason, national fleets running across multiple states need each state's rulebook on hand, not only the federal baseline.
The Core Hours of Service Rules Every Driver Must Know
This is the section every dispatcher should have memorized. Get these five numbers right and you cover most day-to-day HOS compliance checks.
11-hour driving limit. After 10 consecutive hours off duty, a driver can drive a maximum of 11 hours. That's driving time specifically — not total on-duty time.
14-hour on-duty window. The clock starts the moment a driver begins any on-duty activity, such as a pre-trip inspection or paperwork. It runs continuously for 14 hours and does not pause for
- Traffic delays
- Detention time at a shipper or receiver
- Fuel stops or paperwork
- Short breaks that don't qualify as off-duty time
Once that 14-hour window closes, driving must stop — even if the driver hasn't used all 11 driving hours yet.
30-minute break requirement. After 8 cumulative hours of driving, drivers must take a 30-minute non-driving break. Drivers can log the break as off-duty, sleeper berth, or on-duty not-driving. The status is flexible; the break itself is mandatory.
60/70-hour weekly limit. Drivers cap out at
- 60 hours on duty within 7 consecutive days (carriers not operating daily)
- 70 hours on duty within 8 consecutive days (carriers operating every day)
The 34-Hour Restart
Taking 34 consecutive hours off duty resets the weekly clock entirely, giving drivers a fresh 60 or 70-hour bucket. There's no cap on how often a driver can use this restart, which makes it one of the most useful tools for fleets managing tight schedules.
Split Sleeper Berth Provision
Drivers can split their required off-duty time using the sleeper berth, provided
- One period is at least 7 hours in the sleeper berth
- The other period is at least 2 hours (in the berth or off-duty)
- Both periods together total at least 10 hours
A 7+2 split alone only adds up to 9 hours — not enough. Use 7+3 or 8+2 splits in training examples so totals clear the 10-hour minimum.
HOS Exemptions and Flexibility Provisions
Not every driver operates under the full 11/14/30/60-70 framework. Several exemptions give qualifying operations more flexibility, though each comes with strict eligibility conditions.
- 150-air-mile short-haul exemption: Drivers who stay within 150 air miles of their reporting location, return there daily, and are released within 14 hours are exempt from detailed RODS. Non-CDL short-haul drivers follow a similar structure.
- 16-hour short-haul exception: Once every 7 days, a qualifying driver who returns to the same reporting location can extend the 14-hour window to 16 hours. They must have used that reporting location for the prior 5 duty tours and not used this exception in the past 6 days.
- Adverse driving conditions: Unforeseen weather or road conditions can extend the driving window by up to 2 hours, allowing the driver to finish the run or reach a safe location.
- Agricultural exemption: Certain agricultural movements within a 150-air-mile radius during planting or harvest periods fall outside Part 395 entirely.
- Emergency exemption: During federally or state-declared emergencies, HOS rules can be temporarily suspended.
None of these are blanket waivers. Miss one condition (the radius, return-to-base requirement, or placarding status) and standard HOS rules apply again in full.
HOS Violations, Penalties, and CSA Impact
When a driver exceeds the 14-hour clock, there's no workaround. The vehicle goes out of service until the driver completes another 10 consecutive hours off duty. Dispatch pressure doesn't change the math.
Most Common Violations
- False or incomplete logs
- Missing ELD records or Record of Duty Status (RODS) when an ELD is required
- Exceeding daily or weekly driving/on-duty limits
- Failing to take the required 30-minute break
Penalty Ranges
Penalties vary widely depending on severity. ELD-specific penalty ranges include:
- Knowingly falsifying ELD logs: up to $12,135, roughly $1,214 per day
- Average fine for improper HOS logging: around $2,867
- Passenger-carrying vehicle violations: up to $26,126
- Violations tied to hazardous materials: up to $182,877
Both drivers and carriers can be held liable. Severity levels (1-5 points per violation) factor into the driver's CSA record.
CSA Impact
HOS Compliance is one of seven CSA Behavior Analysis and Safety Improvement Categories (BASICs). Violations here—especially fatigued driving or outdated duty records—push carrier percentile scores higher. Higher percentiles mean worse safety performance.
FMCSA's Safety Management System updates monthly and keeps violations on record for two years, with recent violations weighted more heavily. A pattern of violations can trigger a full FMCSA audit.
Staying Compliant: Practical Tips for Fleets
Manual logbooks are where most violations start. Automating duty-status tracking removes the guesswork
- Use an ELD or connected GPS tracking system to log duty status automatically and eliminate manual entry errors
- Give dispatch real-time visibility into driver hours and vehicle location, so routes get planned around remaining hours instead of around wishful thinking
- Train drivers regularly on HOS basics, not just at onboarding
- Keep communication open between drivers and dispatch about fatigue or scheduling conflicts before they become violations
Fatigue isn't a minor factor here. The National Safety Council found fatigued drivers are three times more likely to be in an accident, and going 20 hours without sleep affects cognitive function similarly to a 0.08% blood-alcohol level.
That risk is why real-time hour tracking matters. Platforms like Azuga's GPS fleet management software give fleet managers visibility into driver behavior and hours, with alerts when drivers approach HOS limits.
For construction, HVAC, trucking, and other fleets, that visibility helps avoid last-minute compliance scrambles. Azuga customers have seen accident reductions of 38% on average and 57% fewer speeding citations.
Frequently Asked Questions
What happens if I go over my 14-hour clock?
The driver must stop driving immediately and cannot resume until completing another 10 consecutive hours off duty. There's no workaround dispatch can offer. The vehicle is out of service until that rest period is met.
What is the 6 and 9 hour rule?
There's no distinct federal "6 and 9 hour rule" in current FMCSA guidance. This phrase is often confused with the actual Part 395 structure: 11 hours driving, 14-hour window, and a 30-minute break after 8 hours of driving.
What are the most common hours of service violations?
The violations cited most often include
- False logs or missing ELD records
- Exceeding daily or weekly limits
- Skipping the required 30-minute break
- Missing or incomplete Records of Duty Status
What are the hours of service rules in Florida?
Interstate drivers in Florida follow standard federal HOS rules. Qualifying non-placarded intrastate-only drivers follow Florida-specific limits, including a 12-hour driving cap and 70/80-hour weekly limits. Check Florida DOT guidance for full details on eligibility.
Does the 14-hour clock pause for off-duty time?
No. It runs continuously once triggered and doesn't pause for breaks, detention, or paperwork, except during a qualifying sleeper berth split.
What is the 34-hour restart provision?
Taking 34 consecutive hours off duty resets the 60/70-hour weekly clock completely. There's no limit on how often a driver can use this restart.
