FMCSA Violation Code Reference
Browse all Federal Motor Carrier Safety Regulation (FMCSR) violation codes ranked by citation frequency. Filter by BASIC category, OOS eligibility, or search by code number.
Violation Codes
3,146
BASIC Categories
11
Total Cited
13,023,843
Overall OOS Rate
17.5%
BASIC Categories
Select a category to filter
Vehicle Maintenance
21.0%1,339 codes7,809,333 cited
Unsafe Driving
216 codes3,025,638 cited
Hours of Service
16.3%312 codes1,170,331 cited
Driver Fitness
59.9%119 codes493,083 cited
General/Admin
168 codes413,962 cited
Hazardous Materials
28.3%889 codes75,516 cited
Unknown
41 codes18,680 cited
Controlled Substances/Alcohol
97.3%38 codes16,322 cited
Hazardous Materials Compliance
19 codes967 cited
Hours-of-Service Compliance
36.4%2 codes11 cited
Crash Indicator
3 codes
OOS Eligible Only1,339 codes • Page 1 of 27
All Violation Codes
Ranked by citation frequency
| Rank ▼ | Code | Description | OOS | Times Cited ▼ |
|---|---|---|---|---|
| #1 | 393.9(a) | Inoperable required lamps | \u2014 | 660,737 |
| #2 | 396.3(a)(1) | Inspection/repair/maintenance - general | OOS | 236,919 |
| #3 | 396.17C-PI | No proof of periodic inspection | \u2014 | 212,081 |
| #4 | 396.17(c) | No proof of periodic inspection | \u2014 | 198,331 |
| #5 | 393.47E | Slack adjuster defective | \u2014 | 180,363 |
| #6 | 393.9 | Inoperable Required Lamp | \u2014 | 180,097 |
| #7 | 393.11 | Lighting devices/reflectors | \u2014 | 179,734 |
| #8 | 393.78 | Windshield condition defective | \u2014 | 157,894 |
| #9 | 393.47(e) | Slack adjuster defective | OOS | 157,499 |
| #10 | 393.75A3-TAOL | Tires - All others leaking or inflation less than 50% of the maximum inflation pressure on tire not equipped with ATIS | \u2014 | 155,660 |
| #11 | 393.45(b)(2) | Brake tubing/hoses inadequate | \u2014 | 133,588 |
| #12 | 393.75(a)(3) | Tire-flat and/or audible air leak | \u2014 | 130,970 |
| #13 | 393.95(a) | Emergency equipment - fire extinguisher missing/defective | OOS | 105,458 |
| #14 | 396.5(b) | Fuel system leak | OOS | 96,018 |
| #15 | 393.9A-LIL | Inoperable required lamps | \u2014 | 95,458 |
| #16 | 393.53(b) | Steering system components worn | \u2014 | 89,707 |
| #17 | 393.55E-B | Coupling device/towing methods defective | \u2014 | 88,757 |
| #18 | 393.75(c) | Tire tread depth insufficient (other axles) | OOS | 86,013 |
| #19 | 393.45D-B | Brake tubing/hoses inadequate | \u2014 | 81,444 |
| #20 | 396.5B-L | Fuel system leak | \u2014 | 75,503 |
| #21 | 393.45B2-B-AIR | Brake tubing/hoses inadequate | \u2014 | 74,957 |
| #22 | 396.17C | No proof of periodic inspection | \u2014 | 74,506 |
| #23 | 393.45(d) | Brake tubing/hoses inadequate | \u2014 | 72,830 |
| #24 | 393.53B-B | Steering system components worn | \u2014 | 71,891 |
| #25 | 393.78A-WS | Windshield condition defective | \u2014 | 69,791 |
| #26 | 393.75C-TAOTD-LT2/32 | Tire tread depth insufficient (other axles) | \u2014 | 69,715 |
| #27 | 393.60C | Glazing/window obstructions | \u2014 | 67,056 |
| #28 | 393.55(e) | Coupling device/towing methods defective | \u2014 | 66,184 |
| #29 | 393.95F | Emergency Equipment - Stopped vehicle warning devices missing or improper | \u2014 | 64,562 |
| #30 | 393.9A-LCL | Inoperable required lamps | \u2014 | 62,384 |
| #31 | 396.3A1-BOS | BRAKES OUT OF SERVICE: The number of defective brakes is equal to or greater than 20 percent of the service brakes on the vehicle or combination | \u2014 | 61,053 |
| #32 | 393.95(f) | Emergency Equipment - Stopped vehicle warning devices missing or improper | \u2014 | 59,468 |
| #33 | 393.48(a) | Inoperative/defective brakes | OOS | 59,449 |
| #34 | 393.95A1 | Emergency Equipment - Fire Extinguishers - no fire extinguisher present or not properly rated. | \u2014 | 58,993 |
| #35 | 393.95A4-EEUS | Emergency Equipment - Fire Extinguishers - unsecured | \u2014 | 56,906 |
| #36 | 393.45B2UV | Brake tubing/hoses inadequate | \u2014 | 55,783 |
| #37 | 393.9A-LFTSI | Inoperable required lamps | \u2014 | 54,813 |
| #38 | 393.60(c) | Glazing/window obstructions | \u2014 | 53,470 |
| #39 | 393.9A-LLPL | Inoperable required lamps | \u2014 | 53,261 |
| #40 | 393.9TS | Inoperative turn signal | \u2014 | 52,302 |
| #41 | 393.9A-LTSI | Inoperable required lamps | \u2014 | 51,491 |
| #42 | 396.3A1 | Inspection repair and maintenance of parts and accessories | \u2014 | 48,788 |
| #43 | 393.9A-LSML | Inoperable required lamps | \u2014 | 48,457 |
| #44 | 393.9A-LHLI | Inoperable required lamps | \u2014 | 46,453 |
| #45 | 393.95A | Emergency equipment - fire extinguisher missing/defective | \u2014 | 45,423 |
| #46 | 393.9A-LSLI | Inoperable required lamps | \u2014 | 44,965 |
| #47 | 393.45 | Brake tubing/hoses inadequate | OOS | 44,396 |
| #48 | 393.75A3 | Tire-flat and/or audible air leak | \u2014 | 43,804 |
| #49 | 396.5B | Fuel system leak | \u2014 | 42,528 |
| #50 | 393.53B | Steering system components worn | \u2014 | 41,722 |
About Violation Codes
Each violation found during a roadside inspection is assigned a code from the Federal Motor Carrier Safety Regulations (49 CFR Parts 350-399) or Hazardous Materials Regulations (49 CFR Parts 171-180). These codes map to one of seven BASIC categories used in the FMCSA Safety Measurement System (SMS).
Violations flagged as Out-of-Service (OOS) indicate conditions severe enough to remove a vehicle or driver from service until corrected. OOS violations carry more weight in SMS percentile calculations.
Carriers and drivers who believe a violation was recorded in error can file a Request for Data Review (DataQs) through the FMCSA DataQs system.
Data sources & freshness
FMCSA Vehicle Inspections and Violations
Violation event counts are pre-computed from 13M+ inspection records. Counts are refreshed daily.
Unknown freshness