Most carriers have no FMCSA safety rating assigned. FMCSA compliance reviews are not scheduled — they happen when the agency prioritizes a carrier for audit. For the vast majority of carriers you'll encounter in the market, the out-of-service (OOS) rate from roadside inspections is the most concrete safety data you'll find.
This guide explains exactly what OOS rates mean, how to interpret them against national benchmarks, and the specific thresholds that should trigger a carrier rejection.
What Is an OOS Rate?
An out-of-service rate is the percentage of roadside inspections that resulted in the vehicle or driver being immediately placed "out of service" — meaning they were prohibited from continuing to operate until the violation was corrected. OOS orders are issued by state enforcement officers under CVSA (Commercial Vehicle Safety Alliance) standards.
There are three OOS rates tracked for every carrier in the FMCSA database:
- Vehicle OOS rate: Percentage of vehicle inspections where the truck or trailer had a defect serious enough to remove it from service — brake failure, tire blowouts, lighting violations, etc.
- Driver OOS rate: Percentage of driver inspections where the driver was placed OOS — hours of service violations, no valid CDL, drug/alcohol issues, etc.
- Hazmat OOS rate: Percentage of hazmat inspections resulting in an OOS order — applies only to carriers transporting hazardous materials.
OOS rates require a sufficient sample to be meaningful. A carrier with 1 inspection and a 100% OOS rate is not necessarily a dangerous carrier — it may be a single bad day. Reliable OOS rates need at least 5–10 inspections to draw conclusions. CarrierChk shows total inspections alongside rates so you can assess reliability.
National OOS Rate Averages
The CVSA publishes national average OOS rates annually. These are your benchmarks:
| OOS Category | National Average | Caution Threshold | Rejection Threshold |
|---|---|---|---|
| Vehicle OOS Rate | ~21% | above 30% | above 34% |
| Driver OOS Rate | ~5.5% | above 8% | above 10% |
| Hazmat OOS Rate | ~4.5% | above 7% | above 10% |
The thresholds above are guidelines used by many freight brokers and shippers — not an FMCSA-mandated cutoff. Some organizations use stricter thresholds; others give carriers more latitude based on inspection volume and load type. Set your own policy and apply it consistently.
How to Read OOS Rates Correctly
Inspection Count Matters More Than You Think
A carrier with 2 inspections and a 50% vehicle OOS rate may simply have had one bad inspection on a truck that's since been repaired. A carrier with 200 inspections and a 35% OOS rate has a systematic maintenance problem across their fleet. Always look at inspection count before drawing conclusions from the rate.
General rule: treat OOS rates as reliable for carriers with 10+ inspections. For fewer than 5 inspections, note the rate but don't disqualify based on it alone — look at other signals instead.
Vehicle vs. Driver OOS Rates Signal Different Problems
A high vehicle OOS rate points to equipment maintenance failures — worn brakes, defective lighting, tire problems. It suggests a carrier that isn't keeping up with their fleet. A high driver OOS rate points to compliance failures — hours-of-service violations, invalid licenses, driver fatigue. Both are serious, but they suggest different root causes and different risk profiles for your loads.
Trend Over Time
OOS rates on a carrier's FMCSA record represent their full history of inspections, not just recent ones. A carrier that had high OOS rates two years ago but has been clean since may be significantly different from one whose rates have been climbing. Unfortunately, FMCSA's standard record doesn't show time trends — it's a cumulative average. This is a limitation worth noting when reviewing borderline cases.
When OOS Rates Should Disqualify a Carrier
Vehicle OOS Rate Above 34% with 10+ Inspections
This carrier has systematic equipment failures across their fleet. FMCSA flags carriers above 34% vehicle OOS in their Safety Measurement System (SMS), and many insurers and shippers use this threshold as a hard disqualifier. If the national average is 21% and this carrier is at 34%+, their maintenance program is significantly below industry standard.
Driver OOS Rate Above 10% with 10+ Inspections
A driver OOS rate above 10% — nearly double the national average — indicates systemic hours-of-service or compliance issues across the carrier's drivers. This is a liability risk: fatigued drivers cause accidents, and accidents with your load mean cargo claims, shipper complaints, and possible negligent entrustment exposure.
High OOS Rate + New Authority
A carrier with both elevated OOS rates and authority under 6 months has compiled those OOS violations in a very short time — which suggests the problem is severe and ongoing, not historical. New carriers with already-elevated OOS rates are a red flag worth disqualifying without exceptional justification.
Any OOS Rate + Pending Insurance Cancellation
Elevated OOS rates plus a pending insurance cancellation is a combination that signals a carrier in operational trouble. A carrier that can't keep its equipment out of OOS and can't maintain its insurance policy should not be receiving loads.
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Search by DOT or MC Number →OOS Rates in Context — Don't Use Them Alone
OOS rates are a powerful signal, but they work best combined with other data points. Use them alongside:
- Authority status and age: Active authority + high OOS = concerning but bookable with caution. New authority + any OOS violations = red flag.
- FMCSA safety rating: If a safety rating is assigned, it reflects a formal audit. OOS rates are inspection-based and complement — not replace — the safety rating.
- Insurance status: Verify no pending cancellations, regardless of OOS rates.
- Fleet size: A carrier with 50 trucks and 20% vehicle OOS may have isolated issues. A carrier with 2 trucks and 20% vehicle OOS may have systematic problems — one of their trucks has been placed OOS, which is significant at that scale.
Zero inspections is not zero risk. A carrier with no inspections has no OOS rate — and no safety record at all. Don't interpret zero inspections as a clean bill of health. It means the carrier hasn't been inspected, which is common for new authority and rarely-run carriers.
The Practical Takeaway
OOS rates give you the closest thing to an objective safety signal for carriers that haven't been through an FMCSA compliance review. They're not perfect — inspection volume matters, timing matters, and an elevated rate doesn't always mean every load with this carrier is a risk. But they're the best data you have for most carriers in the market.
Set your OOS thresholds in your carrier vetting policy, apply them consistently, and don't override them without documented justification. A carrier that fails your OOS threshold on Monday doesn't become safer because you need a truck on Tuesday.