Glossary
Out-of-service (OOS) rate
When a roadside inspection finds violations severe enough that the vehicle or driver cannot legally continue, that inspection ends in an out-of-service result. A carrier's vehicle OOS rate and driver OOS rate are the percentage of its inspections that ended that way.
The benchmark
FMCSA publishes national averages for comparison; as of April 2026 they sit around 22.3% for vehicles and 6.7% for drivers. A carrier running far above those averages is failing roadside inspections at a rate most carriers are not, and fleetfax flags both its vehicle and driver OOS rates.
The small-sample caveat
One caveat baked into fleetfax's methodology: rates computed from a handful of inspections are noise. A carrier with three inspections and one OOS result isn't "33% OOS" in any meaningful sense, so fleetfax weighs sample size before flagging rather than alarming you with small-sample arithmetic.
Not the same thing as an OOS order
The OOS rate is a report card on individual inspections. An out-of-service order is a federal shutdown of the whole carrier. Conflating them is one of the most common vetting mistakes; the rate describes performance, the order describes legal status.
Related terms
Out-of-service (OOS) order
A federal order prohibiting a carrier from operating at all, issued for causes like an imminent-hazard finding, a final Unsatisfactory rating, or failure to maintain insurance. An absolute disqualifier while active.
Roadside inspection (levels 1 to 6)
An enforcement officer's examination of a truck, its driver, or both, at weigh stations and roadside stops. The most abundant safety evidence in the public record; results feed OOS rates and CSA scoring.
CSA & the BASICs
FMCSA's safety scoring system: seven behavior categories. Official percentiles are hidden from the public for all seven; the raw data behind five of them is public.
fleetfax reads public FMCSA data and is not affiliated with FMCSA or the U.S. Department of Transportation. This page explains terminology; it is not legal advice.