A 0% OOS Rate Means Nothing on Three Inspections

MC-1257341 had a 0% vehicle OOS rate when my colleague pulled their SAFER sheet. Clean record. Eleven months of active authority, small fleet, not one vehicle parked at a roadside inspection.

He tendered a flatbed load — 47,000 pounds of industrial equipment, valued at $190,000 — and the carrier picked it up.

They'd been inspected four times.

Four inspections in eleven months across three trucks. That's not a safety record. That's a sample size you can't trust.

The problem with running one number

Most brokers do some version of the same check: pull SAFER, find the OOS rate, compare it against the national average — roughly 20% for vehicles, around 5.5% for drivers — and if the carrier is under that threshold, they pass. Next carrier.

The flaw isn't the threshold. It's that an OOS rate is a ratio, and ratios need denominators.

If a carrier passes three inspections and fails one, their vehicle OOS rate is 25%. If they pass 40 and fail 10, their OOS rate is also 25%. Both carriers show the same number on SAFER. One of them has actual data behind it. The other has a sample size that can swing from 0% to 100% on a single inspection.

Here's what makes it worse: SAFER shows you the OOS rate right on the front page of the carrier snapshot. You have to click into the inspection history to see the count. I watch brokers not click. They see 0%, they move on.

The three-number signal I actually use

I've started thinking about carrier vetting as a three-part read, not a one-number pass/fail:

Authority age tells you how long this carrier has been operating under this MC. A carrier running eight years has built a track record, a customer base, and a maintenance history. A carrier at thirteen months has had maybe two or three lease renewals on equipment, probably one or two insurance cycles, and if something went wrong early on, it might have been absorbed into new-authority noise. Age is context for everything else.

OOS rate tells you what happened when enforcement actually showed up. Vehicle OOS means something was wrong enough with the truck or trailer to park it on the spot — brakes, tires, lighting, load securement, whatever the inspector found. Driver OOS means the driver couldn't keep driving — hours-of-service exhausted, license issue, controlled substance, medical certificate problem. Vehicle and driver OOS are different categories of problem and should be read separately, not combined into one headline number.

Inspection count is the number that validates the rate. This is the one most brokers don't look at. Fewer than 10 inspections on a carrier under 18 months old with a small fleet tells you the OOS rate is statistically unreliable. It could look great because they got lucky, or because they're running regional lanes with lower enforcement contact. It could look bad because they had one bad week with a problem that's since been corrected. You can't tell which from the rate alone.

When I see all three trending the wrong way at once — young authority, elevated OOS rate, thin inspection count — that's not three separate flags I'm weighing against each other. That's one flag from three angles.

Why the clean-but-thin profile worries me most

Here's the counterintuitive one: a carrier with a 0% OOS rate and four inspections makes me more careful than a carrier with a 10% OOS rate and 50 inspections.

The carrier with 50 inspections and 10% OOS — I can see the trend. I know what type of violations they're accumulating. I can look at whether the rate is improving or deteriorating. I have data.

The carrier with four inspections and 0% OOS has essentially no signal. They could be a clean operation running safe equipment with good drivers. Or they could be running lanes where enforcement contact is infrequent, haven't gotten unlucky yet, and I'm about to be their first significant load. I genuinely don't know. And "I don't know" isn't a green light; it's a question I need to answer some other way.

What the federal fitness framework actually says

Under 49 CFR § 385.5, FMCSA's safety fitness determination considers crash rates, OOS rates, and safety management practices. The national OOS averages they publish are comparison thresholds built from the full carrier population — carriers of all ages, sizes, and operational profiles.

A 14-month-old carrier with 4 inspections isn't really in that population yet. They haven't been statistically tested in any meaningful way. Comparing their OOS rate against the national average is like comparing a college pitcher's ERA after one outing to a major-league ERA leader. The denominator isn't there.

The MCS-150 form — required under 49 CFR § 390.19 — gives you fleet size and driver count as self-reported by the carrier. The number of inspections relative to fleet size and authority age is one of the first things I eyeball. A carrier running 8 power units between Chicago and Memphis gets inspected more often than the same carrier running 8 trucks regionally in a low-enforcement state. If inspection count seems low relative to what I'd expect for that fleet size and geography, I note it.

How I actually use this when I'm looking at a carrier

I pull the inspection history — not just the summary OOS rate, but the actual inspection count and what the violations were. If the count is fewer than 10 and the carrier is under 18 months old, I'm treating the OOS rate as a directional indicator at best, not a verdict.

Then I look at violation categories. Vehicle OOS violations that repeat across multiple inspections — same brake issue, same lighting problem — tell me something about how this carrier handles maintenance. One violation in three inspections that was corrected is different from the same violation type appearing in inspections three months apart.

Driver OOS is a harder flag. An HOS violation on one driver at one inspection could be an outlier. Two driver OOS events across a small inspection sample, especially if they're the same category (unqualified driver, medical certificate, controlled substance), is a pattern I'm not going to dismiss because the OOS rate still shows under 20%.

I also check what BASIC percentiles exist. Young carriers with thin inspection histories often have blank or low-percentile BASICs because FMCSA hasn't collected enough data to score them. That's not a clean bill of health — it's an absence of data. If there's enough to populate an Unsafe Driving or HOS Compliance BASIC, I treat it as directional even if it's not statistically robust. A young carrier already showing in the 60th percentile on Unsafe Driving with 6 inspections is telling me something.

When I'm still not comfortable, I pick up the phone. Not to quiz them. Just to talk through the load — where it's picking up, drop specifics, any weight or securement requirements. You learn a lot from how that conversation goes. A dispatcher who knows the load type and asks smart questions is different from one who's copying down my instructions without knowing what they're moving.

A scenario where the headline number led someone the wrong way

DOT-3581047. Fourteen months old. Vehicle OOS rate of 6.7% on 15 inspections. Fleet of 8 power units.

Most brokers see 6.7% — well under the 20% threshold — and pass them. But 15 inspections in 14 months on 8 trucks is actually above-average enforcement contact. These guys were getting checked. Frequently. And 6.7% OOS on 15 inspections means one out of every 15 times enforcement looked, a vehicle got parked.

The broker who tendered to them compared 6.7% against the national average, saw it come in under, and filed it as clean. What the broker didn't note was that brake adjustment violations appeared in two of those fifteen inspections — same category, different inspections, months apart. Uncorrected maintenance pattern.

Two months after that tender, the carrier had a crash on I-44. Post-crash inspection found brake deficiencies on two of the three vehicles at the terminal. The carrier's insurance covered the direct claim. The broker got served with a negligent-selection suit under state tort law — which is now fully available to plaintiffs since Montgomery v. Caribe Transport II took preemption off the table in May.

The plaintiff's lawyer subpoenaed the broker's carrier file, pulled the FMCSA inspection history, and showed the jury that publicly available records showed a recurring brake issue across multiple inspections. The broker had none of that in the file. Just a screenshot of the OOS rate.

How I document this

When I screen a carrier, I capture three numbers in my vetting record: authority age at the time of tender, total inspection count in the last 24 months, and the OOS rate split between vehicle and driver. I note the national average for both vehicle and driver OOS at that point in time for comparison.

If the inspection count is fewer than 10 and the carrier is under 18 months old, I add a notation in plain language: "thin inspection history — OOS rate unreliable as standalone signal." That's my reminder to go look at violation codes rather than stop at the percentage.

If I see repeating violation categories across inspections, I write down the specific codes and how many times they appear. If I called the dispatcher, I note that and what came out of the conversation.

DOTScreener pulls this all together in one place — inspection count, OOS split, BASIC percentiles, authority age — so I'm not clicking between four screens on SAFER to piece the picture together. The carrier file shows it as one record I can screenshot and attach to the tender.

The documentation goal isn't to prove the carrier was perfect. It's to show that I asked the right questions and made a reasoned judgment with what was available. One number never tells you the whole story. Write down the whole story.

— Mason Lavallet

Founder, DOTScreener.com