Hours of Service (HOS)
Federal FMCSA regulations in 49 CFR Part 395 that limit commercial motor vehicle drivers' driving and on-duty time to prevent fatigue-related crashes.
TL;DR
Rules limiting CMV drivers to 11 hours driving/14 hours on-duty daily, with 60/70-hour weekly caps and mandatory rest breaks.
Key Points
- ✓11-hour driving limit and 14-hour on-duty window after 10 consecutive hours off duty
- ✓30-minute break required after 8 hours of driving time, can be off-duty, sleeper berth, or on-duty not driving
- ✓60/70-hour weekly limits with 34-hour restart option to reset the weekly calculation
- ✓ELD requirements for automatic time tracking and enforcement, with exemptions for certain short-haul operations
Hours of Service (HOS) Regulations
Hours of Service (HOS) are federal FMCSA safety regulations in 49 CFR Part 395 that limit how long commercial motor vehicle drivers can drive and be on duty, prescribing minimum rest periods to prevent fatigue-related crashes. These regulations apply to most CMV drivers operating in interstate commerce in vehicles weighing 10,001+ lbs GVW/GCW, transporting placarded hazardous materials, or designed to transport 9+ passengers for compensation.
Core HOS Rules for Property-Carrying Drivers
The current HOS framework, updated by FMCSA's 2020 final rule effective September 29, 2020, establishes four key limits:
- 11-hour driving limit: Drivers may drive a maximum of 11 hours after 10 consecutive hours off duty
- 14-hour driving window: Drivers cannot drive after 14 consecutive hours on duty following 10 hours off, regardless of actual driving time
- 30-minute break requirement: Drivers must take at least 30 consecutive minutes off driving after 8 cumulative hours of driving time
- 60/70-hour weekly limits: 60 hours in 7 consecutive days if carrier doesn't operate daily, or 70 hours in 8 consecutive days if operating daily
34-Hour Restart and Reset Rules
Drivers can reset their 60/70-hour calculation by taking at least 34 consecutive hours off duty. FMCSA removed earlier requirements for specific time periods within the restart, so any 34+ consecutive hours off duty now resets the weekly clock. This flexibility allows drivers to manage their schedules more effectively while maintaining safety standards.
On-Duty vs Off-Duty Time Classifications
On-duty time includes driving, vehicle inspection, waiting to be dispatched, loading/unloading, completing shipping paperwork, drug/alcohol testing, and any paid work. Off-duty time requires drivers to be relieved of all work responsibilities. The sleeper berth rule allows drivers to satisfy the 10-hour off-duty requirement with two separate periods: one of at least 7 consecutive hours in the sleeper berth and another off-duty period of at least 2 consecutive hours, with neither period counting against the 14-hour driving window.
2020 HOS Final Rule Changes
FMCSA's most recent major revision expanded the short-haul exception radius to 150 air-miles (from 100) and allows a 14-hour work shift under the exception. The rule also expanded adverse driving conditions allowances, modified the 30-minute break to be triggered by driving time rather than on-duty time, and enhanced sleeper-berth flexibility with split periods.
Key Exemptions and Special Cases
Several exemptions provide operational flexibility: the short-haul exception for CDL drivers operating within 150 air-miles exempts them from break requirements and ELD use. The 16-hour exception allows extending the driving window once every 7 days for drivers returning to the same location. Adverse driving conditions permit extending both driving time and the driving window by up to 2 hours when unexpected conditions arise after dispatch.
Enforcement and Compliance
State and federal inspectors enforce HOS during roadside inspections, audits, and investigations. Violations can result in drivers being placed out-of-service, civil penalties ranging from $1,100 to $16,000 per violation, safety rating downgrades, and increased insurance costs. Most interstate CMV drivers must use ELDs to automatically record driving time, helping enforce the 11/14 and 60/70 rules by tracking driving, on-duty, off-duty, and sleeper-berth statuses in real time.
Passenger-Carrying Vehicle Differences
Passenger-carrying drivers face different limits: 10-hour driving limit after 8 consecutive hours off duty, 15-hour on-duty limit, and the same general weekly 60/70-hour framework. These stricter limits reflect the higher safety standards required when transporting passengers.
Current Pilot Programs and Future Changes
FMCSA is exploring additional flexibility through pilot programs, including a proposed "pause the 14-hour clock" pilot allowing drivers to pause their driving window once per duty period for up to 3 hours while off duty. A planned 2026 pilot program involving approximately 500 drivers will test options to pause the 14-hour clock and explore additional sleeper-berth splits beyond current models.
Safety and Statistical Context
FMCSA research links driver fatigue with increased crash risk, particularly during extended duty periods and night driving. The current HOS framework reduced the previous maximum 82-hour workweek by 12 hours, aiming to reduce fatigue and improve long-term health outcomes. DOT's 2024-2026 learning agenda notes that detention time at shippers and receivers interacts with HOS limits and may threaten safety by compressing available driving time.
Practical Implications
Drivers must constantly manage multiple timing constraints, using breaks and sleeper time strategically. HOS limits can force staging short of destinations when parking or delivery windows conflict with the 14-hour rule. Carriers must design dispatch, routing, and appointment times around HOS constraints, implement robust ELD management systems, and address shipper/receiver detention policies that directly impact HOS compliance. Violations immediately affect CSA scores, employability, insurance premiums, and operational efficiency.