What 393.61 means in plain language
FMCSR 393.61 addresses the condition and presence of side windows on your truck cab. The regulation requires that your vehicle's side windows be adequate—meaning they must be present, intact, and functional. A citation under this code typically means an inspector found one or more side windows to be missing, cracked, shattered, or otherwise compromised in a way that affects visibility, safety, or structural integrity of the cab.
This is not about tinting or aesthetics. The focus is on whether the windows do their job: allowing you to see your surroundings safely and protecting the cab from weather and debris. If a window is broken, missing entirely, or so damaged that it significantly impairs your view of the road or your blind spots, you are in violation.
What our enforcement data actually shows
Across our 13 million roadside inspection records, 393.61 has generated 374 all-time citations, ranking #1015 of 3,036 FMCSR codes by citation volume. In the last 12 months, we recorded 88 citations; in the last 90 days, 25. This is a relatively uncommon citation—most drivers will never see one.
The good news: only 1 citation out of 373 resulted in an out-of-service order, giving this code a 0.3% OOS rate. That's dramatically lower than the all-FMCSR average of 31.4%. In other words, inspectors almost never remove you from service for a window issue. You will typically receive a citation requiring correction within a set timeframe, but you can usually continue operating.
The citation trend over the past 12 months shows modest fluctuation: we saw peaks in December 2025 (11 citations) and February 2026 (11 citations), with lower counts in May, June, and September. This suggests the violation is not concentrated in a single season or region, but occurs sporadically year-round.
Who gets cited most
Our inspection records show enforcement is heavily concentrated in Texas, with 50 citations recorded in the last 180 days and a 0.0% OOS rate there. This represents the vast majority of citations in our dataset, though we lack comparable multi-state breakdowns for other major trucking corridors in this period.
Among carriers, our data shows operations such as FERROSRB SA DE CV (USDOT 4027419) and ARSENIO ELIZONDO QUIROGA (USDOT 3023987) each with 4 all-time citations under this code. Several other carriers—SANTOS ISMAEL DOMINGUEZ OVALLE, HLH LOGISTICS INC, SERVICIOS ESPECIALIZADOS ALANIS SA DE CV, GUEKA LOGISTICS LLC, and GUILLERMO ESQUER GARCIA—each have 3 citations. These numbers are small in absolute terms and do not suggest systemic failure; rather, they reflect the rarity of the violation across the carrier universe.
How severe is this compared to similar codes
Window and visibility-related violations fall within the Vehicle Maintenance category. When we compare 393.61 to peer codes, the differences in enforcement intensity are stark:
393.9 (Inoperable Required Lamp) has drawn 180,097 citations with a 6.9% OOS rate—far more common and more likely to result in removal from service. 393.78 (Windshield condition defective) shows 157,894 citations with a 0.3% OOS rate, nearly identical to 393.61, suggesting that window and windshield defects are treated lightly in enforcement.
By contrast, 396.3(a)(1) (Inspection/repair/maintenance—general) has accumulated 236,919 citations with a 45.3% OOS rate, indicating that maintenance violations with broader scope are far more likely to trigger out-of-service action. The low OOS rate for 393.61 tells us inspectors view side window defects as correctable issues that do not immediately prevent safe operation.
How to avoid it
Prevent 393.61 citations with these concrete pre-trip actions:
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Walk around your entire cab before departure. Stop at each side window, look for cracks, missing glass, or loose frames. Test that windows open and close smoothly without binding or rattling; binding can indicate frame damage.
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Check all four side windows, not just the driver's side. Our enforcement data shows citations are issued regardless of which window is defective. Don't assume the passenger window is less critical.
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Repair or replace damaged windows immediately. If you spot a chip or crack on a pre-trip, do not defer it. Unlike a burned-out marker lamp, a window defect can worsen rapidly in transit and will fail inspection.
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Pay attention to frame and gasket integrity. A window that rattles, leaks, or sits loose in its frame is as much a violation as broken glass. Inspect the rubber seals and mounting hardware.
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If your truck commonly appears in high-citation vehicle makes, prioritize window checks. Our data shows Freightliners (77 citations), Kenworths (25 citations), and Peterbilts (18 citations) dominate the citation list. If you drive one of these brands, be especially vigilant about window condition as part of your routine maintenance.
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Note the co-occurring violations. Our recent inspection data shows 393.61 is often cited alongside inoperable lamps (393.9, 11 shared inspections in 90 days) and missing fire extinguishers (393.95A, 9 shared inspections). This suggests inspectors finding a window defect often conduct a thorough cab inspection. A single defect should prompt you to verify all cab systems—lights, emergency equipment, wipers, mirrors—before your next roadside interaction.
A 393.61 citation is not career-threatening and carries minimal enforcement consequence, but it is preventable through basic pre-trip discipline. Five minutes of cab inspection can save you a citation and the cost of a repair order at a truck stop.