Hours of Service (HOS) regulations are among the most strictly enforced FMCSA rules for commercial truck drivers. These regulations limit how long drivers may operate a commercial motor vehicle and require specific rest periods to reduce fatigue-related accidents.

HOS violations are a leading cause of roadside citations, audit findings, and out-of-service orders.

What Are Hours of Service Rules?

Hours of Service rules define the maximum driving and on-duty time allowed for commercial drivers within a given period. These limits are designed to prevent driver fatigue and improve roadway safety.

Most interstate commercial drivers are subject to daily and weekly limits on driving time, on-duty time, and required off-duty rest. These rules apply regardless of whether a driver is paid by the mile, hour, or load.

For foundational compliance context, see: What Is DOT Compliance?

Key HOS Limits Drivers Must Follow

FMCSA regulations establish specific limits on driving and on-duty time. Drivers must track their hours accurately and ensure they do not exceed allowable limits before operating a vehicle.

Hours of Service compliance is monitored primarily through electronic logging devices (ELDs), which automatically record driving time. Logs must accurately reflect a driver’s duty status and be supported by consistent records.

Failure to follow HOS limits or maintain accurate logs is treated as a serious compliance violation.

How HOS Is Enforced

HOS rules are enforced during roadside inspections, safety audits, and compliance reviews. Inspectors review log data, supporting documents, and ELD records to identify violations.

Repeated HOS violations can trigger audits and increased enforcement scrutiny. Patterns of non-compliance may also affect a carrier’s safety profile and risk rating.

For audit-related risks, see: DOT Audits: What Triggers a Compliance Audit?

Common HOS Compliance Mistakes

Common HOS violations include exceeding driving limits, failing to take required rest breaks, and maintaining inaccurate or incomplete logs. Inconsistencies between logs and supporting documents often result in citations.

Maintaining HOS compliance requires consistent log review, accurate recordkeeping, and a clear understanding of applicable limits. Proper HOS management is a critical component of FMCSA compliance.

For related enforcement patterns, see: Common DOT Violations and How to Avoid Them