Top OOS Violations
The violation codes most frequently resulting in an out-of-service (OOS) order during FMCSA roadside inspections. An OOS order means the vehicle or driver cannot operate until the defect is corrected.
Violations Ranked
50
Total Citations
4,051,432
Total OOS Events
1,489,376
BASIC Categories
4
Why OOS Matters
An out-of-service order is the most severe immediate consequence of a roadside inspection violation. It means the vehicle or driver is deemed too dangerous to continue operating. The vehicle stays parked until repairs are made, costing carriers time and revenue. Repeated OOS violations directly impact a carrier's BASIC percentiles and can trigger FMCSA interventions including compliance reviews and operational shutdowns.
The OOS rate column shows what percentage of times this violation was cited that it resulted in an OOS order. A 100% OOS rate means every citation of that code results in the vehicle or driver being taken out of service.
Top 50 OOS-Triggering Violations
Ranked by total OOS event count
50 violations ranked
fmcsa-violations
| # | Code | Description | BASIC Category | Times Cited | OOS Count | OOS Rate | Risk |
|---|---|---|---|---|---|---|---|
| 1 | 393.75A3-TAOL | Tires - All others leaking or inflation less than 50% of the maximum inflatio… | Vehicle Maintenance | 155,660 | 152,541 | 9800.0% | Critical |
| 2 | 393.75(a)(3) | Tire-flat and/or audible air leak | Vehicle Maintenance | 130,970 | 127,553 | 9739.0% | Critical |
| 3 | 396.3(a)(1) | Inspection/repair/maintenance - general | Vehicle Maintenance | 236,919 | 107,347 | 4531.0% | Medium |
| 4 | 393.9(a) | Inoperable required lamps | Vehicle Maintenance | 660,737 | 101,445 | 1535.0% | Low |
| 5 | 396.3A1-BOS | BRAKES OUT OF SERVICE: The number of defective brakes is equal to or greater … | Vehicle Maintenance | 61,053 | 60,511 | 9911.0% | Critical |
| 6 | 393.9A-LTSI | Inoperable required lamps | Vehicle Maintenance | 51,491 | 50,400 | 9788.0% | Critical |
| 7 | 383.23(a)(2) | CDL - wrong class | Driver Fitness | 50,385 | 49,564 | 9837.0% | Critical |
| 8 | 395.8A1-HOSP | HOS (Property) - Failing to have a record of duty status using the method pre… | Hours of Service | 52,266 | 48,549 | 9289.0% | Critical |
| 9 | 391.41APC | Medical (Certificate) - Operating a property-carrying vehicle without a valid… | Driver Fitness | 49,539 | 48,126 | 9715.0% | Critical |
| 10 | 383.23A2-LCDLN | License (CDL) - Operate a CMV and does not possess a valid CDL | Driver Fitness | 47,123 | 46,457 | 9859.0% | Critical |
| 11 | 393.75A3 | Tire-flat and/or audible air leak | Vehicle Maintenance | 43,804 | 40,713 | 9294.0% | Critical |
| 12 | 395.8(a)(1) | Not using the appropriate method to record hours of service | Hours of Service | 39,561 | 36,861 | 9318.0% | Critical |
| 13 | 393.9A-LSLIWR | Inoperable required lamps | Vehicle Maintenance | 37,274 | 36,841 | 9884.0% | Critical |
| 14 | 393.45B2-BHTD | Brake tubing/hoses inadequate | Vehicle Maintenance | 33,075 | 30,845 | 9326.0% | Critical |
| 15 | 393.45 | Brake tubing/hoses inadequate | Vehicle Maintenance | 44,396 | 27,525 | 6200.0% | High |
| 16 | 393.75(a) | Tires/tubes - general defects | Vehicle Maintenance | 26,907 | 25,369 | 9428.0% | Critical |
| 17 | 393.45(b)(2) | Brake tubing/hoses inadequate | Vehicle Maintenance | 133,588 | 24,893 | 1863.0% | Low |
| 18 | 396.3A1BOS | BRAKES OUT OF SERVICE: The number of defective brakes is equal to or greater … | Vehicle Maintenance | 23,333 | 23,305 | 9988.0% | Critical |
| 19 | 393.100B-C | Cargo securement - aggregate working load | Vehicle Maintenance | 23,086 | 22,715 | 9839.0% | Critical |
| 20 | 383.23A2 | Operating a CMV without a CDL | Driver Fitness | 21,829 | 21,513 | 9855.0% | Critical |
| 21 | 392.9A2-C | Cargo - Vehicle components or dunnage not secured | Unsafe Driving | 21,774 | 20,980 | 9635.0% | Critical |
| 22 | 395.8(e)(1) | 395.8(e)(1) | Hours of Service | 78,276 | 20,370 | 2602.0% | Medium |
| 23 | 393.43 | Brake - relay emergency valve | Vehicle Maintenance | 23,816 | 19,467 | 8174.0% | Critical |
| 24 | 393.43DBMA | Brake - relay emergency valve | Vehicle Maintenance | 19,105 | 18,934 | 9910.0% | Critical |
| 25 | 393.9TS | Inoperative turn signal | Vehicle Maintenance | 52,302 | 18,866 | 3607.0% | Medium |
| 26 | 393.207(a) | Suspension defective | Vehicle Maintenance | 25,723 | 17,671 | 6870.0% | High |
| 27 | 393.75A3-TAOLTIS | Tires - All others leaking in tread area and inflation less than 50% of the m… | Vehicle Maintenance | 17,254 | 16,911 | 9801.0% | Critical |
| 28 | 393.100(b) | Cargo securement - aggregate working load | Vehicle Maintenance | 16,155 | 15,622 | 9670.0% | Critical |
| 29 | 391.11B2-Q | Driver cannot satisfy the English language proficiency requirements of 391.1… | Driver Fitness | 23,688 | 15,440 | 6518.0% | High |
| 30 | 393.75(g) | 393.75(g) | Vehicle Maintenance | 15,809 | 14,766 | 9340.0% | Critical |
| 31 | 393.43D-B | Brake - relay emergency valve | Vehicle Maintenance | 14,687 | 14,414 | 9814.0% | Critical |
| 32 | 396.5(b) | Fuel system leak | Vehicle Maintenance | 96,018 | 14,111 | 1470.0% | Low |
| 33 | 393.45D-BAAL | Brake tubing/hoses inadequate | Vehicle Maintenance | 16,256 | 14,046 | 8641.0% | Critical |
| 34 | 392.9(a)(2) | Failing to secure vehicle equipment | Unsafe Driving | 13,279 | 12,792 | 9633.0% | Critical |
| 35 | 393.43(d) | Brake - relay emergency valve | Vehicle Maintenance | 13,151 | 12,720 | 9672.0% | Critical |
| 36 | 393.75G-TAOW | Tires - All others weight carried exceeds tire load limit | Vehicle Maintenance | 12,798 | 12,711 | 9932.0% | Critical |
| 37 | 393.9 | Inoperable Required Lamp | Vehicle Maintenance | 180,097 | 12,388 | 688.0% | Low |
| 38 | 396.5B-HWSL | Fuel system leak | Vehicle Maintenance | 21,028 | 11,671 | 5550.0% | High |
| 39 | 393.75A | Tires/tubes - general defects | Vehicle Maintenance | 12,699 | 11,431 | 9001.0% | Critical |
| 40 | 393.41-BNPB | Brake - Inoperative or missing parking brake on power unit | Vehicle Maintenance | 11,613 | 11,419 | 9833.0% | Critical |
| 41 | 391.11(b)(4) | No valid medical certificate | Driver Fitness | 11,706 | 11,171 | 9543.0% | Critical |
| 42 | 395.8E-HOSPDOOS | False record of duty status | Hours of Service | 19,092 | 11,062 | 5794.0% | High |
| 43 | 393.41 | No or defective parking brake system on CMV | Vehicle Maintenance | 11,285 | 10,689 | 9472.0% | Critical |
| 44 | 396.3A1-BALR | Air Brake - Fails air loss rate test | Vehicle Maintenance | 10,585 | 10,318 | 9748.0% | Critical |
| 45 | 393.75C-TAOTD-LT1/32 | Tire tread depth insufficient (other axles) | Vehicle Maintenance | 16,050 | 10,028 | 6248.0% | High |
| 46 | 392.2 | Operating a CMV while ill or fatigued | Unsafe Driving | 1,208,164 | 9,691 | 80.0% | Low |
| 47 | 393.75(a)(1) | Tire-ply or belt material exposed | Vehicle Maintenance | 23,264 | 9,492 | 4080.0% | Medium |
| 48 | 393.48(a) | Inoperative/defective brakes | Vehicle Maintenance | 59,449 | 9,292 | 1563.0% | Low |
| 49 | 393.209(d) | Wheel fasteners loose/missing | Vehicle Maintenance | 10,483 | 9,225 | 8800.0% | Critical |
| 50 | 393.45(d) | Brake tubing/hoses inadequate | Vehicle Maintenance | 72,830 | 8,605 | 1182.0% | Low |
OOS Violations by BASIC Category
Which safety categories produce the most shutdowns
Vehicle Maintenance
1,136,800
37 violation codes
Driver Fitness
192,271
6 violation codes
Hours of Service
116,842
4 violation codes
Unsafe Driving
43,463
3 violation codes
Data sources & freshness
FMCSA Violation & Inspection Records
OOS determinations are made by individual inspectors and may vary by jurisdiction. Some violations are almost always OOS-eligible by regulation; others depend on severity assessed at the scene.
Unknown freshness