Hours of Service (HOS)
Hours of Service regulations are federal rules established by the FMCSA under 49 CFR Part 395 that limit the number of hours a commercial motor vehicle driver may drive and work before taking mandatory rest breaks. The rules are designed to prevent fatigue-related crashes by ensuring drivers get adequate rest. HOS compliance is monitored through Electronic Logging Devices (ELDs) and is one of the most frequently inspected areas during roadside stops and DOT audits.
The current Hours of Service rules for property-carrying CMV drivers include several key limits: a driver may drive a maximum of 11 hours after 10 consecutive hours off duty; the 14-hour driving window begins when the driver starts any work activity and cannot be extended with off-duty time; a mandatory 30-minute break is required after 8 cumulative hours of driving; and the 60/70-hour limit restricts total on-duty time over a rolling 7-day or 8-day period. Drivers may restart the 60/70-hour clock by taking 34 or more consecutive hours off duty.
Since December 2017, most CMV drivers have been required to use Electronic Logging Devices to record their driving time. ELDs automatically capture driving data when the vehicle is in motion, reducing the potential for falsification that existed with paper logbooks. The ELD mandate applies to most carriers and drivers subject to HOS rules, with limited exceptions for short-haul drivers, driveaway-towaway operations, and vehicles manufactured before the year 2000.
HOS violations are among the most common findings during roadside inspections and are a significant factor in CSA scoring. A driver found operating beyond HOS limits faces an out-of-service order, meaning they must stop driving immediately and rest for the required period before resuming. Carriers accumulate HOS violation points in their CSA profile, and patterns of violations can trigger FMCSA intervention. Proper scheduling and dispatch practices, combined with real-time ELD monitoring, help carriers maintain HOS compliance and avoid the operational disruptions and financial penalties associated with violations.