What 390.21TC means in plain language
390.21TC addresses marking and identification requirements for commercial motor vehicles. Specifically, it concerns the display of the motor carrier's name on the vehicle. Federal regulations require that the legal name of the motor carrier operating the vehicle be displayed prominently so that it is legible and visible during daylight hours from a safe distance.
This is an administrative compliance issue, not a safety defect. The regulation exists so that law enforcement, shippers, receivers, and the public can quickly identify who operates a particular truck. If your vehicle is missing the carrier name, displays it in a way that's illegible, or shows it in a location where it cannot be read from a reasonable distance, you can be cited.
The violation does not require the vehicle to be placed out of service, and it does not directly affect your ability to operate. However, it is a recordable citation that will appear on your inspection history and your carrier's safety record.
What our enforcement data actually shows
Across our 13 million+ inspection records, 390.21TC has generated 1,296 all-time citations, placing it at rank #651 out of 3,036 FMCSR codes by citation volume. In the last 12 months, we recorded 225 citations, and in the most recent 90-day period, 51 citations.
The out-of-service rate for 390.21TC is extraordinarily low: only 1 vehicle out of 1,295 cited was placed out of service, yielding a 0.1% OOS rate. This is dramatically below the all-FMCSR average of 31.4%. This tells you that inspectors almost never deem this violation severe enough to sideline a vehicle immediately—it is treated as a paperwork/compliance matter, not a safety emergency.
Monthly citation counts over the last 12 months have ranged from 9 to 30, showing consistent but modest enforcement activity. There is no clear seasonal spike; citations remain fairly steady throughout the year.
Who gets cited most
Our data from the last 180 days shows three states leading in 390.21TC citations: Iowa with 84 citations, Illinois with 25, and North Carolina with 2. All three states have recorded a 0.0% out-of-service rate, meaning no vehicles cited in these states for 390.21TC were pulled out of service.
Among all carriers in our all-time database, United Parcel Service Inc (USDOT 21800) leads with 6 citations, followed by Tiger Lines LLC (USDOT 80289), Thor Trucking LLC (USDOT 1730282), and Meroem Auto Transportation LLC (USDOT 4277057), each with 5 citations. Our data shows fleets such as these have encountered this citation multiple times, though the low OOS rate indicates these are routine compliance corrections rather than systemic safety concerns.
How severe is this compared to similar codes
390.21TC sits within a family of marking and identification requirements. Peer codes in the same category show much higher citation volumes but identical or nearly identical OOS rates:
- 390.21TB2-DOT has recorded 74,663 citations (57 times more than 390.21TC) with a 0.0% OOS rate.
- 390.21T(b) shows 61,097 citations with a 0.0% OOS rate.
- 390.21TB1-MC totals 59,189 citations, also at 0.0% OOS.
Even 390.21(b) (USDOT number not displayed), which has 13,244 citations, maintains a 0.0% OOS rate. In other words, 390.21TC is less frequently cited than its peer codes but carries the same practical consequence: it is almost never an out-of-service violation. This uniformity across the marking-requirement category reflects that these are administrative deficiencies, not safety threats.
How to avoid it
Based on patterns in our inspection data, here are concrete steps to prevent 390.21TC citations:
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Pre-trip visual check of carrier name display: Before each shift, walk around your vehicle and verify that your carrier's legal name is clearly visible on both sides of the cab or trailer. The name should be legible from at least 50 feet away in daylight. If paint is faded, faded lettering is peeling, or the name is partially obscured by dirt or damage, report it for repair immediately.
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Understand your carrier's approved marking standard: Ask your dispatcher or safety manager for the exact lettering style, size, color, and location your carrier uses. Some carriers use door decals, others use painted lettering. Know what "correct" looks like for your specific vehicle.
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Inspect after repairs or repainting: If your cab or trailer has been repainted, repaired, or had decals replaced, do a detailed check before taking the road. Shops sometimes miss or misapply the carrier name.
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Note common co-occurring violations: Our data shows that 390.21TC frequently appears alongside record-of-duty-status violations (395.8E), missing shipping documents, and missing or defective emergency equipment. While these are separate issues, they suggest that poorly maintained or non-compliant vehicles are more likely to have marking problems too. A thorough pre-trip that includes reviewing your logs, checking equipment, and verifying vehicle markings addresses multiple risk areas at once.
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Pay special attention if operating a Freightliner, Ford, or International: Our citation data shows these makes represent the majority of 390.21TC citations (304, 136, and 110 respectively). If you drive one of these, add carrier-name legibility to your daily walk-around checklist.
If you have been cited for 390.21TC, the violation is correctable. Ensure the carrier name is properly displayed and legible, photograph the corrected marking, and retain that evidence. Most carriers will allow you to request a review of the citation once the defect is remedied.