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Safety & Compliance 5 min read• Updated: September 2026

What Does Out of Service (OOS) Mean? FMCSA Orders Explained

Understand Federal Out-of-Service Orders, driver and vehicle OOS rates, and why operating under an OOS order is a severe federal violation.

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1. Understanding Out-of-Service (OOS) Orders

An Out-of-Service (OOS) order is a formal regulatory directive issued by the FMCSA or state law enforcement prohibiting a motor carrier, commercial vehicle, or driver from operating on public highways until specific safety violations are resolved.

There are two primary categories of OOS occurrences: roadside inspection OOS conditions and federal administrative OOS orders.

2. Driver vs. Vehicle OOS Rates

Roadside inspection data tracks how frequently a carrier's drivers or equipment are placed out of service during random North American Standard inspections:

  • Driver OOS Rate: Measures violations such as Hours-of-Service (HOS) log non-compliance or improper licensing. National average is approximately 5.51%.
  • Vehicle OOS Rate: Measures equipment safety issues like brake defects, bald tires, or lighting malfunctions. National average is approximately 20.72%.

Frequently Asked Questions

Can a carrier operate while under a Federal OOS Order?

No. Operating under a federal OOS order is illegal and subjects the entity to substantial federal civil penalties and immediate vehicle impoundment.

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