Out-of-Service Violations Explained

An out-of-service (OOS) order is a formal enforcement action that prohibits a driver from operating, a vehicle from moving, or both until the condition that triggered the order is corrected. They’re issued during roadside inspections, and they carry real consequences: the driver is parked, the load is delayed, and the OOS violation goes on your CSA record.

Understanding what triggers OOS conditions — and how to avoid them — is part of operating a compliant trucking business.

Driver OOS vs. Vehicle OOS

There are two types of OOS orders:

Driver OOS means the driver cannot operate any commercial motor vehicle until the condition is corrected. Common causes:

• Hours of Service violations (exceeded driving hours, falsified logs)
• No valid medical examiner’s certificate, or certificate is expired; this should be caught in your driver qualification file
• Drug or alcohol test failure or refusal during an inspection
• Possession of a controlled substance in the cab
• No valid CDL, or CDL doesn’t cover the vehicle being operated
• Operating under an OOS order from a prior inspection

Vehicle OOS means the specific vehicle cannot move until the defect is corrected. Common causes:

• Brake system failures (brake adjustment out of spec, air leaks, failed components)
• Tire defects (underinflation, cuts, tread depth below minimum)
• Lighting failures (required lights non-functional)
• Steering system defects
• Coupling device failures (king pin, fifth wheel, safety chains)
• Load securement violations
• Failed or missing safety equipment (fire extinguisher, triangles)

In many inspections, a driver OOS and a vehicle OOS occur simultaneously — the driver can’t operate, and the vehicle can’t move.

What Triggers a Roadside Inspection

Officers may stop a vehicle for inspection based on:

• Random selection at a weigh station
• Moving violation observed by enforcement
• Visible equipment defect (light out, damaged vehicle)
• CSA score or inspection history flagging the carrier for closer attention
• Specific enforcement campaigns targeting lanes or commodity types

You cannot control when you’re selected for inspection. You can control whether you fail one.

Common Vehicle OOS Conditions

Brakes are the most frequent vehicle OOS condition. Brake adjustment, air pressure loss rates, and component condition are inspected closely. Understand your brake adjustment specifications and check them regularly. Brakes that were fine last week can be out of adjustment after a hard stop.

Tires: Tread depth minimums apply per axle position, and sidewall damage or low pressure triggers OOS. Check tires at every pre-trip inspection — not just visually, but with a gauge.

Lights: All required lights — headlights, brake lights, turn signals, marker lights, clearance lights — must function. A single burned-out brake light is a violation. Carry spare bulbs.

Load securement: Improperly secured freight can result in OOS. Know the cargo securement rules for your commodity type (49 CFR Part 393).

What to Do When Placed OOS

Don’t argue with the officer. An OOS order is a legal finding. Disputing it roadside doesn’t reverse it and can make the interaction worse.

Get written documentation. You’re entitled to a copy of the inspection report, which lists every violation found and whether each is an OOS condition. Keep this documentation.

Correct the condition before moving. For vehicle OOS, the vehicle must be repaired before it moves. If the defect can be corrected roadside (brake adjustment, replacing a light), do so and have the officer verify the repair. If not, the vehicle must be towed or a mobile repair must come to you.

For driver OOS due to HOS: You are parked until you have the required off-duty time. The freight waits. Call your broker immediately to explain the situation and get a delivery extension.

For driver OOS due to medical certificate: You cannot drive until a valid certificate is obtained. This means getting a physical exam from a certified Medical Examiner. This can take time — it’s why keeping your medical certificate current and not letting it expire is critical.

CSA Score Impact

OOS violations are weighted significantly higher than non-OOS violations in the FMCSA’s CSA scoring system. For a new carrier with few total inspections on record, a single OOS event can create a BASIC score above the intervention threshold.

Check your CSA scores at ai.fmcsa.dot.gov/sms after any inspection to see how it affected your standing. Monitor scores monthly — you want to catch trends early, before they trigger a DOT compliance review.

The good news: clean inspections also improve your CSA standing. Every inspection that closes without violations is a positive data point. Pre-trip inspections aren’t just a regulatory requirement — they’re your defense against OOS conditions that damage your business, and they’re a major part of New Entrant Safety Audit readiness.

Frequently Asked Questions

Can I move my truck to a safe location if placed out of service?

If the vehicle is already in a safe location (pulled off at a weigh station or inspection site), you generally cannot drive it further until the OOS condition is resolved. If you're in an unsafe location on the road, enforcement may allow you to move to the nearest safe location. Do not assume you can drive to a repair shop without authorization — ask the officer specifically.

How long does an OOS violation stay on my record?

FMCSA CSA data uses a rolling 24-month window for scoring. Violations older than 24 months fall out of the calculation. However, they remain in your inspection history indefinitely. Serious violations may be factored into safety rating decisions beyond the standard scoring window.

Does an OOS violation automatically raise my CSA scores?

Yes. OOS violations are weighted heavily in the CSA BASIC scoring system — significantly more than non-OOS violations in the same category. A single OOS condition can meaningfully move your BASIC scores, particularly for a new carrier with few total inspections on record.