Direct answers on 390.21TC enforcement, out-of-service risk, and what to do after a citation. Data from 13M+ roadside inspections.
Ranks #663 of 3,146 FMCSR codes by citation frequency • OOS rate of 0.1% is below the FMCSR-wide average of 33.3%.
Improper size/location/color of required CMV marking(s).
Direct answers grounded in TruckCodex inspection data
No. Across our 13 million inspection records, 390.21TC resulted in out-of-service placement in only 1 case out of 1,296 all-time citations, for an OOS rate of 0.1%. This is far below the national FMCSR average of 31.4% across all codes. The overwhelming majority of drivers cited for 390.21TC are allowed to continue operating.
First, photograph or document the violation clearly. Then review the citation details against your logbook and records. Our data shows 390.21TC frequently co-occurs with false records of duty status (395.8E, 14 shared inspections in the last 90 days) and missing log entries (395.8A-ELD, 6 co-occurrences). Check your hours-of-service logs and electronic logs for gaps or discrepancies. Request a copy of the inspection report and contact your company's compliance team or attorney if the citation appears incorrect.
390.21TC is cited unevenly across the country. Iowa leads by far with 84 citations in the last 180 days, followed by Illinois with 25 and North Carolina with 2. If you operate in Iowa, you're in a high-enforcement zone for this code. If you're elsewhere, the citation is much rarer—390.21TC ranks #651 out of 3,036 FMCSR codes nationally, meaning it accounts for less than 0.1% of all traffic violations.
Compared to similar administrative codes, 390.21TC is low-severity. The 0.1% OOS rate is effectively zero risk of roadside out-of-service action. Related codes like 390.21TB2-DOT (74,663 citations, 0.0% OOS), 390.21T(b) (61,097 citations, 0.0% OOS), and 390.21TB1-MC (59,189 citations, 0.0% OOS) all carry 0.0% OOS rates as well. This code is administrative in nature and rarely results in immediate vehicle removal.
Yes, 390.21TC citations can often be contested through the DataQs (FMCSA's online dispute system) if the finding is factually incorrect or if documentation was missing at the time of inspection but has since been obtained. Because 390.21TC is administrative—not a safety equipment or driver behavior violation—focus your challenge on whether the officer properly verified the condition at the time of inspection. If you have contradictory documentation, upload it to DataQs immediately. Response time matters: submit within 90 days of citation.
Citations have remained steady over the last 12 months, with 225 total citations and no out-of-service placements. Monthly volume ranges from 9 to 30 citations, with recent months (February and March 2026) showing 23 and 25 citations respectively. The pattern suggests consistent enforcement rather than a sudden surge, so this is not an emerging hot-button violation—just ongoing, routine administrative oversight.
Freightliners dominate the citation records with 304 all-time citations, followed by Ford (136), International (110), Peterbilt (100), and Kenworth (99). If you drive a Freightliner, you're statistically in a higher-citation group for this violation. This may reflect fleet size or operating patterns rather than mechanical defect; review your unit's prior citation history to identify patterns.
When 390.21TC is cited, inspectors frequently find related documentation issues in the same roadside stop. False records of duty status (395.8E) co-occurred in 14 of the last 90 days' inspections, and missing manual log entries (395.24C2III) appeared in 10. Equipment also flags together: emergency equipment deficiencies (393.95A) in 7 inspections and inoperable lamps (393.9) in 6. If you receive a 390.21TC citation, ask the officer specifically about your hours-of-service documentation and lights—those are the likeliest follow-ups.
Where 390.21TC is most commonly cited (last 180 days)
Other violations commonly found on the same inspection (last 90 days)
TruckCodex aggregates official public-sector datasets. See the Source registry for dataset-level coverage and the Freshness log for last-import timestamps.
Census, SAFER, SMS, Licensing & Insurance (L&I), roadside inspections, crashes, and authority history.
Vehicle recall campaigns, defect investigations, and consumer safety complaints (SCRS).
Cross-border carrier registry and Canadian recall campaigns where applicable.
TruckCodex is an independent aggregator; it is not affiliated with FMCSA, NHTSA, EIA, or Transport Canada. Always verify compliance-critical information directly with the originating agency.