What 393.67 means in plain language
FMCSR 393.67 targets tire conditions that go beyond the obvious blowout or flat — specifically the kind of damage that makes a tire a structural failure waiting to happen. If an inspector finds fabric showing through the rubber, or spots a bulge, bump, or cut that exposes the tire's internal structure, you're looking at a 393.67 citation.
The rule exists because these conditions signal that the tire's integrity has already been compromised. A bulge in the sidewall, for example, means the cords inside have partially separated. A cut deep enough to expose the fabric means the protective layers are gone. Neither condition is safe at highway speeds, and inspectors are trained to look for exactly these signs during roadside Level I and II inspections.
This is not a paperwork violation — it's a physical condition on your vehicle. That matters because it affects whether you get placed out of service on the spot and how the citation scores against your CSA record.
What our enforcement data actually shows
Across our database of 13 million+ inspections, 393.67 has generated 2,479 all-time citations, with 1,308 of those coming in just the last 12 months and 608 in the last 90 days alone. That recent acceleration is notable — the 90-day count represents nearly half of the entire past year's volume.
Of all 2,479 historical citations, 477 resulted in the driver being placed out of service, for an OOS rate of 19.2%. To put that in context, the all-FMCSR average OOS rate across every code in our database is 31.4%. So 393.67 sits meaningfully below that average — inspectors do not automatically park a truck for this violation. That said, nearly 1 in 5 citations still ends with the vehicle parked, which is not a number to dismiss.
The code ranks #490 out of 3,036 FMCSR codes by citation volume, putting it in the top 17% of all codes for enforcement frequency. It carries a CSA severity weight of 6, and because it is OOS-eligible, any citation — whether or not you were actually parked — lands on your PSP record and feeds into your carrier's Vehicle Maintenance BASIC score.
Looking at the monthly trend, citations spiked sharply in late 2025 and early 2026: December 2025 saw 164 citations, January 2026 brought 113, February 2026 hit 253, and March 2026 reached 288. That is a dramatic four-month run compared to the 55–72 range seen earlier in the year, suggesting heightened enforcement focus on tire condition during that period.
Who gets cited most
Our inspection records show Texas is by far the dominant enforcement state for 393.67, with 911 citations in the last 180 days — dwarfing every other state in the dataset. Illinois comes in a distant second with 8 citations, followed by Iowa with 2 citations.
The OOS-rate variation across these states is striking and worth understanding. Texas, despite its massive citation volume, has an OOS rate of only 10.1% — meaning most Texas citations are written without parking the truck. Illinois, by contrast, shows a 62.5% OOS rate across its 8 citations, more than six times higher than Texas. New Mexico's single citation in the 180-day window resulted in an OOS order, putting its rate at 100.0%. If you're running through Illinois or New Mexico, inspectors there appear far more likely to pull you out of service for the same physical tire condition that a Texas inspector might write up and send you on your way.
Our data shows fleets such as AUTOLINEAS PERZA SA DE CV (USDOT 3346939) with 63 all-time citations and MANTENIMIENTO LIMOSA SA DE CV (USDOT 4182303) with 50 all-time citations appear frequently in the 393.67 record, indicating that cross-border operations are heavily represented in this violation's history.
How severe is this compared to similar codes
Within the Vehicle Maintenance category, 393.67's 2,479 all-time citations is a fraction of what some peer codes generate, but its OOS exposure is real compared to several high-volume codes.
Consider 393.9(a) — Inoperable Required Lamps — which has accumulated 660,737 citations in our database with a 15.4% OOS rate. That code gets cited roughly 267 times more often than 393.67, but its OOS rate is actually lower. If you're trying to prioritize pre-trip attention, tire defects under 393.67 carry a higher OOS probability than a burned-out lamp.
Look at 393.78 — Windshield Condition Defective — which shows 157,894 citations and a 0.3% OOS rate. That code is cited far more frequently but almost never results in a parking order. A bulging tire is a fundamentally different enforcement outcome than a cracked windshield.
Then there is 396.3(a)(1) — the general Inspection, Repair and Maintenance code — sitting at 236,919 citations with a 45.3% OOS rate. That code's OOS rate is more than double 393.67's, which tells you that when inspectors write the broader maintenance violation alongside a specific tire defect, the consequences compound quickly.
How to avoid it
The co-occurrence patterns in our data tell a clear story about what kind of inspections generate 393.67 citations. In the last 90 days, 393.67 showed up alongside 393.95A (missing or defective fire extinguisher) in 88 shared inspections, alongside 396.3A1 (general maintenance deficiencies) in 92 shared inspections, and alongside 393.65F (flat or audibly leaking tires) in 73 shared inspections. These are vehicles that have multiple unresolved maintenance issues — not isolated tire problems. Here is what you can do before and during every pre-trip:
- Walk every tire with intent, not habit. Run your hand along sidewalls and look for bulges or bumps that break the smooth profile. A bulge you can feel in 30 seconds at the terminal is an OOS order you don't get at the scale.
- Look for fabric, not just pressure. Cuts that expose the cord structure are a 393.67 trigger even if the tire holds air. Check tread edges and sidewalls for any cut deeper than surface rubber.
- Check your co-violation exposure at the same time. Our data shows that 393.9 (inoperable lamps, 91 shared inspections) and 393.11 (lighting devices, 57 shared inspections) commonly appear alongside this tire code. If your tires are rough, your lights probably haven't been checked either. Do both.
- Pay extra attention to KW and Freightliner units. Our database shows Kenworth vehicles account for 432 all-time 393.67 citations and Freightliner (FRHT) for 356 — the two most-cited makes by a significant margin. If you operate either, tire condition should be a named checklist item, not an afterthought.
- Don't leave brake and fuel systems for the shop to catch. With 393.45B2UV (brake tubing and hoses, 53 shared inspections) and 396.5B (fuel system leaks, 63 shared inspections) co-occurring frequently, a tire inspection that also catches a hose issue can prevent a multi-violation report that turns a severity-6 citation into a much larger CSA problem.