Federal Motor Carrier Safety Administration (FMCSA) roadside inspections are examinations of commercial motor vehicles (CMVs) and/or drivers by Motor Carrier Safety Assistance Program (MCSAP) inspectors. MCSAP inspectors conduct roadside inspections on CMVs and drivers to check that they are in compliance with the Federal Motor Carrier Safety Regulations and/or Hazardous Materials Regulations.
If an inspection results in a serious violation, the driver will be issued an Out-of-Service (OOS) order. These violations must be corrected before the driver or vehicle can return to service. The FMCSA keeps a close eye on the most common vehicle violations. This data can be used to maintain a safe fleet and keep your business in compliance with the rules of the road. Here are the 10 most common OOS orders issued during the 2020 fiscal year for vehicle violations.
| Description of Violation | Violation Code | # of OOS Orders |
| 1. Tire-flat and/or audible air leak. | 393.75A3 | 70,884 |
| 2. Brakes out of service – The number of defective brakes is equal to or greater than 20% of the service brakes on the vehicle or combination. | 396.3A1BOS | 48,201 |
| 3. Inoperative turn signal. | 393.9TS | 41,193 |
| 4. No/improper breakaway or emergency braking. | 393.43 | 26,241 |
| 5. Inoperable required lamp. | 393.9 | 25,427 |
| 6. Flat tire or fabric exposed. | 393.75A | 15,987 |
| 7. Brake tubing and hose adequacy. | 393.45 | 14,456 |
| 8. Inspection, repair and maintenance of parts and accessories. | 396.3A1 | 14,190 |
| 9. Axle positioning parts defective/missing. | 393.207A | 13,594 |
| 10. Inoperative brake lamps. | 393.9BRKLAMP | 12,408 |
